Scholars@Duke
Michael J Mehl

Michael J Mehl

Assistant Research Professor in the Thomas Lord Department of Mechanical Engineering and Materials Science
Thomas Lord Department of Mechanical Engineering and Materials Science
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Selected Publications

The AFLOW library of crystallographic prototypes: Part 4

Journal Article Computational Materials Science · May 1, 2024 The AFLOW Library of Crystallographic Prototypes has been updated to include an additional 683 entries, which now reaches 1,783 prototypes. We have also made some changes to the presentation of the entries, including a more consistent definition of the AFL ... Full text Cite

Disordered enthalpy-entropy descriptor for high-entropy ceramics discovery.

Journal Article Nature · January 2024 The need for improved functionalities in extreme environments is fuelling interest in high-entropy ceramics1-3. Except for the computational discovery of high-entropy carbides, performed with the entropy-forming-ability descriptor4, m ... Full text Cite

High-temperature superconductivity in the Ca-Sc-H system

Journal Article Physical Review B · December 1, 2023 The discovery of high critical temperature Tc in compressed H3S has been followed by the prediction and experimental confirmation of even higher superconducting temperatures with Tc approaching room temperature in LaH10 and CaH6. These works established th ... Full text Cite

aflow++: A C++ framework for autonomous materials design

Journal Article Computational Materials Science · January 25, 2023 The realization of novel technological opportunities given by computational and autonomous materials design requires efficient and effective frameworks. For more than two decades, aflow++ (Automatic-Flow Framework for Materials Discovery) has provided an i ... Full text Cite

aflow.org: A web ecosystem of databases, software and tools

Journal Article Computational Materials Science · January 5, 2023 To enable materials databases supporting computational and experimental research, it is critical to develop platforms that both facilitate access to the data and provide the tools used to generate/analyze it — all while considering the diversity of users’ ... Full text Cite

AFLOW-XtalFinder: a reliable choice to identify crystalline prototype

Journal Article npj Computational Materials · December 1, 2021 The accelerated growth rate of repository entries in crystallographic databases makes it arduous to identify and classify their prototype structures. The open-source AFLOW-XtalFinder package was developed to solve this problem. It symbolically maps structu ... Full text Cite

The AFLOW Library of Crystallographic Prototypes: Part 3

Journal Article Computational Materials Science · November 1, 2021 The AFLOW Library of Crystallographic Prototypes has been extended to include a total of 1,100 common crystal structural prototypes (510 new ones with Part 3), comprising all of the inorganic crystal structures defined in the seven-volume Strukturbericht s ... Full text Cite

Settling the matter of the role of vibrations in the stability of high-entropy carbides.

Journal Article Nature communications · September 2021 High-entropy ceramics are attracting significant interest due to their exceptional chemical stability and physical properties. While configurational entropy descriptors have been successfully implemented to predict their formation and even to discover new ... Full text Cite

Tin-pest problem as a test of density functionals using high-throughput calculations

Journal Article Physical Review Materials · August 1, 2021 At ambient pressure tin transforms from its ground state, the semimetal α-Sn (diamond structure), to metallic β-Sn at 13°C (286 K). There may be a further transition to a simple hexagonal phase, γ-Sn, above 450 K. These relatively low transition temperatur ... Full text Cite

Automated coordination corrected enthalpies with AFLOW-CCE

Journal Article Physical Review Materials · April 1, 2021 The computational design of materials with ionic bonds poses a critical challenge to thermodynamic modeling since density functional theory yields inaccurate predictions of their formation enthalpies. Progress requires leveraging physically insightful corr ... Full text Cite

Pressure-induced high-temperature superconductivity in hypothetical H3X (X=As, Se, Br, Sb, Te and I) in the H3S structure with Im3¯m symmetry

Journal Article Journal of Physics and Chemistry of Solids · April 1, 2020 The discovery of high critical temperature Tc superconductivity in highly compressed H3S has opened up the question of searching for strong electron–phonon coupling in the hydrides outside the transition metal series. The specific objective of this work is ... Full text Cite

High-temperature superconductivity in LaH10

Journal Article Physical Review B · February 1, 2020 The recent discovery of a high critical temperature Tc in compressed H3S has been followed by the prediction of Liu et al. of Tc≈250 K in the clathrate LaH10 structure. This report has been confirmed experimentally by Somayazulu et al. and Drozdov et al. A ... Full text Cite

A Brief History of Strukturbericht Symbols and Other Crystallographic Classification Schemes

Conference Journal of Physics: Conference Series · October 30, 2019 In 1913, x-ray crystallography was first used to determine the crystal structure of diamond. Since that time hundreds of thousands, if not millions, of crystal structures have been determined. Published structures require critical review and indexing to ma ... Full text Cite

Theoretical studies of the vibrational properties of octahedrane (C12H12): A polyhedral caged hydrocarbon molecule.

Journal Article The Journal of chemical physics · June 2019 The vibrational properties of octahedrane (C12H12) are calculated using density-functional theory employing two different computational methods: an all-electron Gaussian orbital approach and a Naval Research Laboratory-tight-binding s ... Full text Cite

The AFLOW Library of Crystallographic Prototypes: Part 2

Journal Article Computational Materials Science · April 15, 2019 Materials discovery via high-throughput methods relies on the availability of structural prototypes, which are generally decorated with varying combinations of elements to produce potential new materials. To facilitate the automatic generation of these mat ... Full text Cite

AFLOW-CHULL: Cloud-Oriented Platform for Autonomous Phase Stability Analysis.

Journal Article Journal of chemical information and modeling · December 2018 A priori prediction of phase stability of materials is a challenging practice, requiring knowledge of all energetically competing structures at formation conditions. Large materials repositories-housing properties of both experimental and hypothetical comp ... Full text Cite

AFLOW-SYM: platform for the complete, automatic and self-consistent symmetry analysis of crystals.

Journal Article Acta crystallographica. Section A, Foundations and advances · May 2018 Determination of the symmetry profile of structures is a persistent challenge in materials science. Results often vary amongst standard packages, hindering autonomous materials development by requiring continuous user attention and educated guesses. This a ... Full text Cite

A tight-binding molecular dynamics study of the noble metals Cu, Ag and Au

Journal Article Computational Materials Science · April 15, 2018 We have used the Naval Research Lab (NRL) tight-binding (TB) method to study the electronic and mechanical properties of the noble metals. In order to perform molecular dynamics simulations, we used new TB parameters that work well at smaller interatomic d ... Full text Cite

Stability and high-temperature superconductivity in hydrogenated chlorine

Journal Article Quantum Studies: Mathematics and Foundations · April 1, 2018 Recent computational studies confirmed by experiment have shown the occurrence of superconductivity in the compound H 3S at a temperature, Tc, near 200 K when the pressure is close to 200 GPa. It has become clear that classic electron–phonon coupling quant ... Full text Cite

Bright triplet excitons in caesium lead halide perovskites.

Journal Article Nature · January 2018 Nanostructured semiconductors emit light from electronic states known as excitons. For organic materials, Hund's rules state that the lowest-energy exciton is a poorly emitting triplet state. For inorganic semiconductors, similar rules predict an analogue ... Full text Cite

The AFLOW library of crystallographic prototypes: Part 4

Journal Article Computational Materials Science · May 1, 2024 The AFLOW Library of Crystallographic Prototypes has been updated to include an additional 683 entries, which now reaches 1,783 prototypes. We have also made some changes to the presentation of the entries, including a more consistent definition of the AFL ... Full text Cite

Disordered enthalpy-entropy descriptor for high-entropy ceramics discovery.

Journal Article Nature · January 2024 The need for improved functionalities in extreme environments is fuelling interest in high-entropy ceramics1-3. Except for the computational discovery of high-entropy carbides, performed with the entropy-forming-ability descriptor4, m ... Full text Cite

High-temperature superconductivity in the Ca-Sc-H system

Journal Article Physical Review B · December 1, 2023 The discovery of high critical temperature Tc in compressed H3S has been followed by the prediction and experimental confirmation of even higher superconducting temperatures with Tc approaching room temperature in LaH10 and CaH6. These works established th ... Full text Cite

aflow++: A C++ framework for autonomous materials design

Journal Article Computational Materials Science · January 25, 2023 The realization of novel technological opportunities given by computational and autonomous materials design requires efficient and effective frameworks. For more than two decades, aflow++ (Automatic-Flow Framework for Materials Discovery) has provided an i ... Full text Cite

aflow.org: A web ecosystem of databases, software and tools

Journal Article Computational Materials Science · January 5, 2023 To enable materials databases supporting computational and experimental research, it is critical to develop platforms that both facilitate access to the data and provide the tools used to generate/analyze it — all while considering the diversity of users’ ... Full text Cite

AFLOW-XtalFinder: a reliable choice to identify crystalline prototype

Journal Article npj Computational Materials · December 1, 2021 The accelerated growth rate of repository entries in crystallographic databases makes it arduous to identify and classify their prototype structures. The open-source AFLOW-XtalFinder package was developed to solve this problem. It symbolically maps structu ... Full text Cite

The AFLOW Library of Crystallographic Prototypes: Part 3

Journal Article Computational Materials Science · November 1, 2021 The AFLOW Library of Crystallographic Prototypes has been extended to include a total of 1,100 common crystal structural prototypes (510 new ones with Part 3), comprising all of the inorganic crystal structures defined in the seven-volume Strukturbericht s ... Full text Cite

Settling the matter of the role of vibrations in the stability of high-entropy carbides.

Journal Article Nature communications · September 2021 High-entropy ceramics are attracting significant interest due to their exceptional chemical stability and physical properties. While configurational entropy descriptors have been successfully implemented to predict their formation and even to discover new ... Full text Cite

Tin-pest problem as a test of density functionals using high-throughput calculations

Journal Article Physical Review Materials · August 1, 2021 At ambient pressure tin transforms from its ground state, the semimetal α-Sn (diamond structure), to metallic β-Sn at 13°C (286 K). There may be a further transition to a simple hexagonal phase, γ-Sn, above 450 K. These relatively low transition temperatur ... Full text Cite

Automated coordination corrected enthalpies with AFLOW-CCE

Journal Article Physical Review Materials · April 1, 2021 The computational design of materials with ionic bonds poses a critical challenge to thermodynamic modeling since density functional theory yields inaccurate predictions of their formation enthalpies. Progress requires leveraging physically insightful corr ... Full text Cite

Pressure-induced high-temperature superconductivity in hypothetical H3X (X=As, Se, Br, Sb, Te and I) in the H3S structure with Im3¯m symmetry

Journal Article Journal of Physics and Chemistry of Solids · April 1, 2020 The discovery of high critical temperature Tc superconductivity in highly compressed H3S has opened up the question of searching for strong electron–phonon coupling in the hydrides outside the transition metal series. The specific objective of this work is ... Full text Cite

High-temperature superconductivity in LaH10

Journal Article Physical Review B · February 1, 2020 The recent discovery of a high critical temperature Tc in compressed H3S has been followed by the prediction of Liu et al. of Tc≈250 K in the clathrate LaH10 structure. This report has been confirmed experimentally by Somayazulu et al. and Drozdov et al. A ... Full text Cite

A Brief History of Strukturbericht Symbols and Other Crystallographic Classification Schemes

Conference Journal of Physics: Conference Series · October 30, 2019 In 1913, x-ray crystallography was first used to determine the crystal structure of diamond. Since that time hundreds of thousands, if not millions, of crystal structures have been determined. Published structures require critical review and indexing to ma ... Full text Cite

Theoretical studies of the vibrational properties of octahedrane (C12H12): A polyhedral caged hydrocarbon molecule.

Journal Article The Journal of chemical physics · June 2019 The vibrational properties of octahedrane (C12H12) are calculated using density-functional theory employing two different computational methods: an all-electron Gaussian orbital approach and a Naval Research Laboratory-tight-binding s ... Full text Cite

The AFLOW Library of Crystallographic Prototypes: Part 2

Journal Article Computational Materials Science · April 15, 2019 Materials discovery via high-throughput methods relies on the availability of structural prototypes, which are generally decorated with varying combinations of elements to produce potential new materials. To facilitate the automatic generation of these mat ... Full text Cite

AFLOW-CHULL: Cloud-Oriented Platform for Autonomous Phase Stability Analysis.

Journal Article Journal of chemical information and modeling · December 2018 A priori prediction of phase stability of materials is a challenging practice, requiring knowledge of all energetically competing structures at formation conditions. Large materials repositories-housing properties of both experimental and hypothetical comp ... Full text Cite

AFLOW-SYM: platform for the complete, automatic and self-consistent symmetry analysis of crystals.

Journal Article Acta crystallographica. Section A, Foundations and advances · May 2018 Determination of the symmetry profile of structures is a persistent challenge in materials science. Results often vary amongst standard packages, hindering autonomous materials development by requiring continuous user attention and educated guesses. This a ... Full text Cite

A tight-binding molecular dynamics study of the noble metals Cu, Ag and Au

Journal Article Computational Materials Science · April 15, 2018 We have used the Naval Research Lab (NRL) tight-binding (TB) method to study the electronic and mechanical properties of the noble metals. In order to perform molecular dynamics simulations, we used new TB parameters that work well at smaller interatomic d ... Full text Cite

Stability and high-temperature superconductivity in hydrogenated chlorine

Journal Article Quantum Studies: Mathematics and Foundations · April 1, 2018 Recent computational studies confirmed by experiment have shown the occurrence of superconductivity in the compound H 3S at a temperature, Tc, near 200 K when the pressure is close to 200 GPa. It has become clear that classic electron–phonon coupling quant ... Full text Cite

Bright triplet excitons in caesium lead halide perovskites.

Journal Article Nature · January 2018 Nanostructured semiconductors emit light from electronic states known as excitons. For organic materials, Hund's rules state that the lowest-energy exciton is a poorly emitting triplet state. For inorganic semiconductors, similar rules predict an analogue ... Full text Cite

Active bialkali photocathodes on free-standing graphene substrates

Journal Article npj 2D Materials and Applications · December 1, 2017 The hexagonal structure of graphene gives rise to the property of gas impermeability, motivating its investigation for a new application: protection of semiconductor photocathodes in electron accelerators. These materials are extremely susceptible to degra ... Full text Cite

The AFLOW Library of Crystallographic Prototypes: Part 1

Journal Article Computational Materials Science · August 1, 2017 An easily available resource of common crystal structures is essential for researchers, teachers, and students. For many years this was provided by the U.S. Naval Research Laboratory's Crystal Lattice Structures web page, which contained nearly 300 crystal ... Full text Cite

High-temperature superconductivity at high pressures for H3SixP1−x, H3PxS1−x, and H3ClxS1−x

Journal Article Journal of Physics and Chemistry of Solids · December 1, 2016 Recent experimental and computational works have established the occurrence of superconducting temperatures, Tc, near 200 K when the pressure is close to 200 GPa in hydrogen-based sulfur compounds. In this work we investigate the effects of phosphorus and ... Full text Cite

The AFLOW standard for high-throughput materials science calculations

Journal Article Computational Materials Science · October 1, 2015 Abstract The Automatic-Flow (AFLOW) standard for the high-throughput construction of materials science electronic structure databases is described. Electronic structure calculations of solid state materials depend on a large number of parameters which must ... Full text Cite

Energy band structure of CuInS2 and optical spectra of CuInS2 nanocrystals

Journal Article Physical Review B - Condensed Matter and Materials Physics · July 27, 2015 Using first principles calculations we describe the energy band structure of bulk CuInS2. The energy band parameters for the multiband effective mass approximation that describes the band edges of this semiconductor are obtained by fitting them to the firs ... Full text Cite

Finding the stable structures of N1-xWx with an ab initio high-throughput approach

Journal Article Physical Review B - Condensed Matter and Materials Physics · May 26, 2015 Using density functional theory calculations, many researchers have predicted that various tungsten nitride compounds N1-xWx (x<12) will be "ultraincompressible" or "superhard," i.e., as hard as or harder than diamond. Necessary conditions for such compoun ... Full text Cite

Cubic H3S around 200 GPa: An atomic hydrogen superconductor stabilized by sulfur

Journal Article Physical Review B - Condensed Matter and Materials Physics · May 19, 2015 The multiple scattering-based theory of Gaspari and Gyorffy for the electron-ion matrix element in close packed metals is applied to Im3¯mH3S, which has been predicted by Duan et al. and Bernstein et al. to be the stable phase at this stoichiometry around ... Full text Cite

What superconducts in sulfur hydrides under pressure and why

Journal Article Physical Review B - Condensed Matter and Materials Physics · February 27, 2015 The recent discovery of superconductivity at 190 K in highly compressed H2S is spectacular not only because it sets a record high critical temperature, but because it does so in a material that appears to be, and we argue here that it is, a conventional st ... Full text Cite

Reply to "comment on 'Application of partition density-functional theory to one-dimensional models' "

Journal Article Physical Review A - Atomic, Molecular, and Optical Physics · February 12, 2014 The Comment by Elliott et al. stresses that partition density-functional theory (PDFT) yields a global partition potential and unique occupation numbers. Our reply points out that both of these results can be obtained, numerically, in model calculations, s ... Full text Cite

First-principles study of the electronic structure of iron-selenium: Implications for electron-phonon superconductivity

Journal Article Physical Review B - Condensed Matter and Materials Physics · January 31, 2014 We have performed density functional theory calculations using the linearized augmented plane wave method (LAPW) with the local density approximation (LDA) functional to study the electronic structure of the iron-based superconductor iron-selenium (FeSe). ... Full text Cite

Tight-Binding study of Boron structures

Journal Article Journal of Physics and Chemistry of Solids · January 1, 2014 We have performed Linearized Augmented Plane Wave (LAPW) calculations for five crystal structures (alpha, dhcp, sc, fcc, bcc) of Boron which we then fitted to a non-orthogonal tight-binding model following the Naval Research Laboratory Tight-Binding (NRL-T ... Full text Cite

Tight-binding studies of bulk properties and hydrogen vacancies in KBH 4

Journal Article Computational Materials Science · August 20, 2013 We present computational studies of the bulk properties and hydrogen vacancies in KBH4 using tight-binding (TB) calculations. The NRL-TB method was used to construct a TB Hamiltonian by fitting the density-functional theory (DFT) data for the electronic en ... Full text Cite

Epitaxial growth of cubic and hexagonal InN thin films via plasma-assisted atomic layer epitaxy

Journal Article Crystal Growth and Design · April 3, 2013 InN thin films possessing either a novel cubic or a hexagonal phase were grown by plasma-assisted atomic layer epitaxy on an a-plane sapphire, Si(111), and GaN/sapphire templates, simultaneously. Two ALE growth temperature windows were found between 175-18 ... Full text Cite

Possible molecular bottom-up approach to optical metamaterials

Journal Article Physical Review B - Condensed Matter and Materials Physics · September 4, 2012 We investigate the possibility of a molecular bottom-up approach to the construction of the basic element for optical negative index metamaterials. Undoped and doped graphene-based molecules, including nanotubes, are considered. We employ first-principles ... Full text Cite

Application of partition density-functional theory to one-dimensional models

Journal Article Physical Review A - Atomic, Molecular, and Optical Physics · July 16, 2012 We have carried out calculations for one-dimensional model systems using the self-consistency algorithm of the recently published partition density-functional theory. The issues of uniqueness of occupation numbers and a relation to the self-consistent atom ... Full text Cite

AFLOW: An automatic framework for high-throughput materials discovery

Journal Article Computational Materials Science · June 1, 2012 Recent advances in computational materials science present novel opportunities for structure discovery and optimization, including uncovering of unsuspected compounds and metastable structures, electronic structure, surface, and nano-particle properties. T ... Full text Cite

Tight-binding study of hcp Zn and Cd

Journal Article Physical Review B - Condensed Matter and Materials Physics · November 28, 2011 We have developed tight-binding Hamiltonians for the hcp transition metals zinc and cadmium based on the Naval Research Laboratory tight-binding method. The Hamiltonians have a nonorthogonal basis and are derived by fitting to band structures and total ene ... Full text Cite

Density functional study of the L10-αIrV transition in IrV and RhV

Journal Article Journal of Alloys and Compounds · January 21, 2011 Both IrV and RhV crystallize in the αIrV structure, with a transition to the higher symmetry L10 structure at high temperature, or with the addition of excess Ir or Rh. Here we present evidence that this transition is driven by the lowering of the electron ... Full text Cite

Anomalously high thermal conductivity of amorphous silicon films prepared by hot-wire chemical vapor deposition

Journal Article Chinese Journal of Physics · January 1, 2011 We report anomalously high thermal conductivities of amorphous Si (a-Si) films prepared by hot-wire chemical-vapor deposition (HWCVD) at the National Renewable Energy laboratory (NREL), that is a factor of 4~6 higher than predicted by the model of minimum ... Cite

Tight-binding Hamiltonian for LaOFeAs

Journal Article Physical Review B - Condensed Matter and Materials Physics · August 4, 2010 First-principles electronic-structure calculations have been very useful in understanding some of the properties of the new iron-based superconductors. Further explorations of the role of the individual atomic orbitals in explaining various aspects of rese ... Full text Cite

First-principles calculations and tight-binding molecular dynamics simulations of the palladium-hydrogen system

Journal Article Physical Review B - Condensed Matter and Materials Physics · May 10, 2010 We present a study of palladium-hydrogen system by the linearized augmented plane-wave (LAPW) and Naval Research Laboratory (NRL) tight-binding (TB) methods. We constructed a TB Hamiltonian by fitting to first-principles LAPW data for the electronic energi ... Full text Cite

Static and dynamic tight-binding simulations of the binary NbMo and CuZr alloys

Journal Article Journal of Alloys and Compounds · August 26, 2009 We applied the NRL-tight-binding method in static and molecular dynamics simulations for determining the electronic and dynamic properties of the binary Nb-Mo and Cu-Zr systems. The tight-binding (TB) Hamiltonians were determined by least-square fits to da ... Full text Cite

Properties of bcc metals by tight-binding total energy simulations

Journal Article Materials Science and Engineering: B · June 25, 2009 Monovacancies of six bcc d-transition metals V, Cr, Nb, Mo, Ta and W have been studied by tight-binding (TB) simulations using the NRL-TB method. This method satisfactorily reproduces the electronic properties, phonon frequencies, thermal expansion coeffic ... Full text Cite

High thermal conductivity of a hydrogenated amorphous silicon film

Journal Article Physical Review Letters · January 20, 2009 We measured the thermal conductivity κ of an 80μm thick hydrogenated amorphous silicon film prepared by hot-wire chemical-vapor deposition with the 3ω (80-300 K) and the time-domain thermoreflectance (300 K) methods. The κ is higher than any of the previou ... Full text Cite

A tight-binding Hamiltonian for band structure and carrier transport in graphene nanoribbons

Conference Materials Research Society Symposium Proceedings · December 1, 2008 To understand nanoribbons of graphene, we developed an ab initio parametrized fit to Carbon and Hydrogen chemical data, out to arbitrary neighbor interactions, including relaxations. Our computed band structure confirms the well-known three-family behavior ... Cite

Electronic structure and superconducting properties of lanthanum

Journal Article Physical Review B - Condensed Matter and Materials Physics · December 1, 2008 The total energy and electronic structure of lanthanum have been calculated in the bcc, fcc, hcp, and double hcp structures for pressures up to 35 GPa. The full-potential linearized-augmented-plane-wave method was used with both the local-density approxima ... Full text Cite

Self-consistent atomic deformation method for application of density functional theory

Journal Article Physical Review B - Condensed Matter and Materials Physics · July 29, 2008 We describe a computational method based on density functional theory in which the total electronic density is expressed as a sum over "atomic" densities or densities localized at atomic sites. The atomic densities are determined self-consistently from a v ... Full text Cite

Nearly metastable rhombohedral phases of bcc metals

Journal Article Physical Review B - Condensed Matter and Materials Physics · February 14, 2008 The energy E(c/a) for a bcc element stretched along its [001] axis (the Bain path) has a minimum at c/a=1, a maximum at c/a=2, and an elastically unstable local minimum at c/a>2. An alternative path connecting the bcc and fcc structures is the rhombohedral ... Full text Cite

Calculations of the superconducting properties of scandium under high pressure

Journal Article Physical Review B - Condensed Matter and Materials Physics · October 23, 2007 In recent years the number of elements in the periodic table that become superconductors under pressure has increased to the point that this is no longer considered a rare phenomenon. Recent experiments suggest that scandium reaches a superconducting tempe ... Full text Cite

From graphene to graphite: A general tight-binding approach for nanoribbon carrier transport

Journal Article Physical Review B - Condensed Matter and Materials Physics · September 27, 2007 In an effort to better understand the behavior of graphene, we developed an ab initio parametrized fit of hydrocarbon interactions, out to arbitrary neighbors, including forces. Our computed bands show that ribbons of graphene have increased numbers of zig ... Full text Cite

Structural distortions in Al F3: A test for density-functional methods

Journal Article Physical Review B - Condensed Matter and Materials Physics · April 30, 2007 The crystal structure of Al F3 at high temperatures has a simple cubic lattice. Below ∼730 K, the structure transforms to a rhombohedral (α -phase) structure with R 3̄ c symmetry due to an unstable R5- phonon. Density-functional based methods, from the leas ... Full text Cite

A methodology to aid in the design of naval steels: Linking first principles calculations to mesoscale modeling

Journal Article Materials Science and Engineering: A · April 15, 2007 This paper provides a brief overview of a multidisciplinary effort at the Naval Research Laboratory aimed at developing a computationally-based methodology to assist in the design of advanced Naval steels. This program uses multiple computational technique ... Full text Cite

Calculations of superconducting properties in yttrium and calcium under high pressure

Journal Article Physical Review B - Condensed Matter and Materials Physics · January 31, 2007 We have used first-principles electronic structure calculations to generate the bulk modulus as a function of volume as well as the densities of states and scattering phase shifts at the Fermi level. These quantities were used in conjunction with the rigid ... Full text Cite

Vibrational modes and diffusion of self-interstitial atoms in body-centered-cubic transition metals: A tight-binding molecular-dynamics study

Journal Article Physical Review B - Condensed Matter and Materials Physics · December 5, 2006 Using a tight-binding molecular-dynamics method, we have calculated the formation energies, diffusivity, and localized vibrational frequencies of self-interstitial atoms (SIA's) in body-centered-cubic (bcc) transition metals: vanadium, niobium, molybdenum, ... Full text Cite

Ab initio based tight-binding molecular dynamics simulation of the sticking and scattering of O 2 Pt(111)

Journal Article Journal of Chemical Physics · May 7, 2006 The sticking and scattering of O2 Pt (111) has been studied by tight-binding molecular dynamics simulations based on an ab initio potential energy surface. We focus, in particular, on the sticking probability as a function of the angle of incidence and the ... Full text Cite

Cyclohexamantane (C26H30): First-principles DFT study of a novel diamondoid molecule

Journal Article Diamond and Related Materials · April 1, 2006 Diamondoids are rigid stable hydrocarbons of unusually high symmetry. The recent isolation of many diamondoids of varying shapes and sizes from petroleum oil has revitalized interest in this field. We show in this work that modern density-functional theory ... Full text Cite

Phase stability in the Fe-Ni system: Investigation by first-principles calculations and atomistic simulations

Journal Article Acta Materialia · September 1, 2005 First-principles calculations of the energy of various crystal structures of Fe, Ni and ordered Fe-Ni compounds with different stoichiometries have been performed by the linearized augmented plane wave (LAPW) method in the generalized gradient approximatio ... Full text Cite

Theoretical confirmation of the experimental Raman spectra of the lower-order diamondoid molecule: Cyclohexamantane (C26H30)

Journal Article Chemical Physics Letters · February 14, 2005 The lower-order diamondoid hydrocarbon molecule, cyclohexamantane (C 26H30), has been recently isolated from distilled Gulf Coast petroleum. While the structure of C26H30 has been confirmed through X-ray diffraction, mass spectroscopy, and 1H/ 13C NMR spec ... Full text Cite

Tight-binding calculations of the band structure and total energies of the various polytypes of silicon carbide

Journal Article Physical Review B - Condensed Matter and Materials Physics · February 1, 2005 We present electronic structure and total energy calculations for SiC in a variety of polytype structures using the NRL nonorthogonal tight-binding method. We develop one set of parameters optimized for a combination of electronic and energetic properties ... Full text Cite

Tetragonal phase transformation in gold nanowires

Journal Article Journal of Engineering Materials and Technology · January 1, 2005 First principle, tight binding, and semi-empirical embedded atom calculations are used to investigate a tetragonal phase transformation in gold nanowires. As wire diameter is decreased, tight binding and modified embedded atom simulations predict a surface ... Full text Cite

Tight-Binding Method in Electronic Structure

Chapter · January 1, 2005 In the linear combination of atomic orbitals (LCAO) method, the one-electron wave function is expressed as a linear combination of Bloch sums. When such an expansion is made to the wave function in the Schrödinger equation, one obtains a set of simultaneou ... Full text Cite

Consequences of zero-point motion to the radial distribution function of amorphous silicon

Conference Journal of Physics Condensed Matter · November 10, 2004 While there have been many studies based on models of amorphous silicon, there have been surprisingly few (perhaps only one) that have seriously addressed the radial distribution function at low temperature. Our work is based in part on the so-called NRL t ... Full text Cite

A tight-binding investigation of the NaxCoO2 Fermi surface

Journal Article Europhysics Letters · November 1, 2004 We perform an orthogonal basis tight-binding fit to an LAPW calculation of paramagnetic NaxCoO2 for several dopings. The optimal position of the apical oxygen at each doping is resolved, revealing a non-trivial dependence of the band structure and Fermi su ... Full text Cite

Application of the NRL tight-binding method to the heavy elements Pb and Po

Journal Article Journal of Physics and Chemistry of Solids · November 1, 2004 We have applied the NRL tight-binding (TB) method to study the mechanical and electronic properties of the heavy elements Pb and Po. The predicted properties include ground-state structure, electronic band structure and elastic moduli. Phonon-dispersion cu ... Full text Cite

Tight-binding study of structure and vibrations of amorphous silicon [41]

Journal Article Physical Review B - Condensed Matter and Materials Physics · October 1, 2004 We present a tight-binding calculation that, for the first time, accurately describes the structural, vibrational and elastic properties of amorphous silicon. We compute the interatomic force constants and find an unphysical feature of the Stillinger-Weber ... Full text Cite

Absence of metastable states in strained monatomic cubic crystals

Journal Article Physical Review B - Condensed Matter and Materials Physics · July 1, 2004 A tetragonal, or Bain path, distortion of a metal with an fcc (bcc) ground state toward the bcc (fcc) structure initially requires an increase in energy, but at some point along the Bain path the energy will again decrease until a local minimum is reached. ... Full text Cite

Electronic properties of NaCdF3: A first-principles prediction

Journal Article Physical Review B - Condensed Matter and Materials Physics · January 8, 2004 Based on first-principles total energy calculations, we predict that NaCdF3 could be formed in a ferroelectric crystal structure. Using a symmetry guided search with structure optimization, we found two ferroelectric structures, nearly degenerate in energy ... Full text Cite

Stability and structural transition of gold nanowires under their own surface stresses

Conference Materials Research Society Symposium Proceedings · January 1, 2004 First-principle, tight binding, and semi-empirical embedded atom calculations are used to investigate a tetragonal phase transformation in gold nanowires. As wire diameter is decreased, tight binding and modified embedded atom simulations predict a surface ... Full text Cite

Interlayer surface relaxations and energies of fcc metal surfaces by a tight-binding method

Journal Article Physical Review B - Condensed Matter and Materials Physics · January 1, 2004 The authors examine the interlayer surface relaxations and surface energies for the low-index faces of fcc Ni, Pd, Rh, Pt, Au, and Ir using the Naval Research Laboratory (NRL) tight-binding (TB) method. We compare the TB calculations, utilizing self-consis ... Full text Cite

Water molecule by the self-consistent atomic deformation method

Journal Article Physical Review B - Condensed Matter and Materials Physics · December 11, 2003 We present a density functional method which expresses the charge density of a system of atoms as a sum over localized atomiclike densities derived from potentials defined variationally from the total energy expression, which includes contributions from ov ... Full text Cite

Electronic structure of the Cu 3 Au(1 1 1) surface

Conference Applied Surface Science · October 15, 2003 Using the NRL-tight binding method, we investigate the electronic structure of the unrelaxed Cu 3 Au(111) surface. The tight binding parameters were determined by fitting to LDA calculations and found to reproduce the surface energy, bulk elastic constants ... Full text Cite

Unified picture of the molecular adsorption process: O2/Pt(1 1 1)

Journal Article Surface Science · August 1, 2003 Tight-binding molecular dynamics simulations of the adsorption of O2/Pt(1 1 1) have been performed based on an ab initio potential energy surface. We demonstrate that, contrary to common belief, in this system the whole adsorption probability as a function ... Full text Cite

Tight-binding simulations of Nb surfaces and surface defects

Journal Article Physical Review B - Condensed Matter and Materials Physics · July 1, 2003 We study the properties of low-index Nb surfaces using the NRL-tightbinding (TB) method. We develop a new TB Hamiltonian for Nb using the basic NRL-TB framework with an expanded fitting database that includes additional bulk structures and frozen phonon ca ... Cite

Superconductivity in compressed potassium and rubidium

Journal Article Solid State Communications · June 1, 2003 Superconductivity in compressed potassium and rubidium was discussed. Band theory and BCS theory were used. Results showed that at high pressures potassium and rubidium would be superconductors with transition temperatures approaching 10 K. ... Full text Cite

The Slater-Koster tight-binding method: A computationally efficient and accurate approach

Journal Article Journal of Physics Condensed Matter · March 19, 2003 In this article we discuss the Slater-Koster (SK) tight-binding (TB) method from the perspective of our own developments and applications to this method. We first present an account of our work in constructing TB Hamiltonians and applying them to a variety ... Full text Cite

Lattice dynamics and elastic properties of corundum by the self-consistent atomic deformation method

Journal Article Physical Review B - Condensed Matter and Materials Physics · December 1, 2002 We apply a recently developed density-functional method based on localized densities to study electronic, structural, elastic, optical, and vibrational properties of α-Al1O3. Although our approach is generally less accurate than conventional band-structure ... Cite

Tight-binding study of high-pressure phase transitions in titanium: Alpha to omega and beyond

Journal Article Europhysics Letters · October 1, 2002 We use a tight-binding total-energy method, with parameters determined from a fit to first-principles calculations, to examine the newly discovered γ phase of titanium. Our parameters were adjusted to accurately describe the αTi-ωTi phase transition, which ... Full text Cite

Calculation of polarization

Journal Article Physical Review B - Condensed Matter and Materials Physics · September 1, 2002 It has been argued that a recent advance in the theory of polarization implies that Clausius-Mossotti type models of polarization, which express polarization in terms of the dipole moments of overlapping atomiclike densities, are fundamentally flawed. Here ... Cite

Nonorthogonal tight-binding model for germanium

Journal Article Physical Review B - Condensed Matter and Materials Physics · August 15, 2002 We present a pair of nonorthogonal tight-binding (TB) models for germanium within the NRL-TB approach. One uses an sp3 basis, and is optimized for total-energy calculations by fitting to the total energy and band structures of several high-symmetry lattice ... Full text Cite

Embedded-atom potential for B2-NiAl

Journal Article Physical Review B - Condensed Matter and Materials Physics · June 1, 2002 An embedded-atom potential has been constructed for the intermetallic compound B2-NiAl by fitting to both experimental properties and ab initio data. The ab initio data have been generated in the form of energy-volume relations for a number of alternative ... Cite

First-principles study of superconductivity in high-pressure boron

Journal Article Physical Review B - Condensed Matter and Materials Physics · May 1, 2002 We study superconductivity in boron using first-principles LAPW calculations, the rigid-muffin-tin approximation, and the McMillan theory. Our results point to an electron-phonon mechanism producing transition temperatures near 10 K at high pressures, in a ... Cite

Tight-binding calculations of the band structure and total energies of the various phases of magnesium

Journal Article Physical Review B - Condensed Matter and Materials Physics · April 1, 2002 Tight-binding calculations for Mg in a variety of crystal structures are reported using the nonorthogonal tight-binding model with parameters selected to fit accurately first-principles results. These parameters correctly predict hcp to be the stable cryst ... Cite

Application of a tight-binding total-energy method for FeAl

Journal Article Journal of Physics Condensed Matter · March 4, 2002 The Naval Research Laboratory tight-binding (TB) method accurately describes the electronic and mechanical properties of many elemental systems, including semiconductors, simple metals, and transition metals. We report an extension of the method to an inte ... Full text Cite

Superconductivity in compressed iron: Role of spin fluctuations

Journal Article Physical Review B - Condensed Matter and Materials Physics · March 1, 2002 The recent discovery of superconductivity in hexagonal iron under pressure poses a question about whether it is of conventional (phonon) or unconventional (magnetic) origin. We present first-principles calculations of the electron-phonon coupling in iron a ... Cite

Analysis of the ferroelectric phase transition in BaAl2O4 by group theoretical methods and first-principles calculations

Journal Article Physical Review B - Condensed Matter and Materials Physics · February 1, 2002 Group theoretical methods are applied to a ferroelectric phase transition in barium aluminate (BaAl2O4). The atomic displacements from x-ray-diffraction data are decomposed into four modes: a primary order parameter and three secondary order parameters. Th ... Cite

Calculation of polarization

Journal Article Physical Review B - Condensed Matter and Materials Physics · January 1, 2002 It has been argued that a recent advance in the theory of polarization implies that Clausius-Mossotti type models of polarization, which express polarization in terms of the dipole moments of overlapping atomiclike densities, are fundamentally flawed. Here ... Full text Cite

Tight-binding calculations of the band structure and total energies of the various phases of magnesium

Journal Article Physical Review B - Condensed Matter and Materials Physics · January 1, 2002 Tight-binding calculations for Mg in a variety of crystal structures are reported using the nonorthogonal tight-binding model with parameters selected to fit accurately first-principles results. These parameters correctly predict hcp to be the stable cryst ... Full text Cite

Superconductivity in compressed iron: Role of spin fluctuations

Journal Article Physical Review B - Condensed Matter and Materials Physics · January 1, 2002 The recent discovery of superconductivity in hexagonal iron under pressure poses a question about whether it is of conventional (phonon) or unconventional (magnetic) origin. We present first-principles calculations of the electron-phonon coupling in iron a ... Full text Cite

First-principles study of superconductivity in high-pressure boron

Journal Article Physical Review B - Condensed Matter and Materials Physics · January 1, 2002 We study superconductivity in boron using first-principles LAPW calculations, the rigid-muffin-tin approximation, and the McMillan theory. Our results point to an electron-phonon mechanism producing transition temperatures near 10 K at high pressures, in a ... Full text Cite

Lattice dynamics and elastic properties of corundum by the self-consistent atomic deformation method

Journal Article Physical Review B - Condensed Matter and Materials Physics · January 1, 2002 We apply a recently developed density-functional method based on localized densities to study electronic, structural, elastic, optical, and vibrational properties of (formula presented) Although our approach is generally less accurate than conventional ban ... Full text Cite

Embedded-atom potential for (formula presented)

Journal Article Physical Review B - Condensed Matter and Materials Physics · January 1, 2002 An embedded-atom potential has been constructed for the intermetallic compound (formula presented) by fitting to both experimental properties and ab initio data. The ab initio data have been generated in the form of energy-volume relations for a number of ... Full text Cite

Analysis of the ferroelectric phase transition in (formula presented) by group theoretical methods and first-principles calculations

Journal Article Physical Review B - Condensed Matter and Materials Physics · January 1, 2002 Group theoretical methods are applied to a ferroelectric phase transition in barium aluminate (formula presented) The atomic displacements from x-ray-diffraction data are decomposed into four modes: a primary order parameter and three secondary order param ... Full text Cite

Electronic structure calculations of lead chalcogenides PbS, PbSe, PbTe

Journal Article Journal of Physics and Chemistry of Solids · January 1, 2002 In this work, we have extended our study of the mechanical properties and the electronic structure of PbTe to include other Pb chalcogenide compounds (PbSe, PbS). The calculations were performed self-consistently using the scalar-relativistic full-potentia ... Full text Cite

Tight-binding description of the electronic structure and total energy of tin

Journal Article Philosophical Magazine B: Physics of Condensed Matter; Statistical Mechanics, Electronic, Optical and Magnetic Properties · January 1, 2002 The Naval Research Laboratory (NRL) tight-binding (TB) method was applied to tin, a material which is known to exist in the diamond structure (α-Sn) at zero temperature and Iow pressures. A smali change in the pressure drives tin to the β-Sn structure, whi ... Full text Cite

Precise tight-binding description of the band structure of MgB2

Journal Article Physical Review B - Condensed Matter and Materials Physics · November 1, 2001 We present a careful recasting of first-principles band-structure calculations for MgB2 in a nonorthogonal sp-tight-binding (TB) basis. Our TB results almost exactly reproduce our full-potential linearized augmented plane-wave results for the energy bands, ... Cite

Effects of C, Cu, and Be substitutions in superconducting MgB2

Journal Article Physical Review B - Condensed Matter and Materials Physics · October 1, 2001 Density functional calculations are used to investigate the effects of partial substitutional alloying of the B site in MgB2 with C and Be alone and combined with substitution of Mg by Cu. The effect of such substitutions on the electronic structure, elect ... Cite

Applications of the NRL tight-binding method to magnetic systems

Journal Article Journal of Applied Physics · June 1, 2001 The NRL developed tight-binding method has been very successful in describing the properties of nonmagnetic elemental metals and semiconductors with accuracy comparable to first-principles methods. In this article we discuss extensions of the method to mag ... Full text Cite

Dynamical properties of Au from tight-binding molecular-dynamics simulations

Journal Article Physical Review B - Condensed Matter and Materials Physics · April 9, 2001 We studied the dynamical properties of Au using our previously developed tight-binding method. Phonon-dispersion and density-of-states curves at T=0 K were determined by computing the dynamical matrix using a supercell approach. In addition, we performed m ... Full text Cite

Transferable tight-binding parameters for ferromagnetic and paramagnetic iron

Journal Article Physica B: Condensed Matter · February 1, 2001 We construct transferable tight-binding (TB) parameters for ferromagnetic and paramagnetic iron by fitting the total energy and the electronic band structure to three prototype crystal structures of Fe (BCC, both ferromagnetic and paramagnetic; and FCC, pa ... Full text Cite

Tight-binding Hamiltonians for realistic electronic structure calculations

Journal Article Physica B: Condensed Matter · February 1, 2001 This article, written in honor of Eleftherios N. Economou, contains a short summary of work one of us carried out some 20 years ago in collaboration with Lefteris and reports on recent developments on the use of tight-binding Hamiltonians to perform accura ... Full text Cite

Precise tight-binding description of the band structure of (formula presented)

Journal Article Physical Review B - Condensed Matter and Materials Physics · January 1, 2001 We present a careful recasting of first-principles band-structure calculations for (formula presented) in a nonorthogonal (formula presented)-tight-binding (TB) basis. Our TB results almost exactly reproduce our full-potential linearized augmented plane-wa ... Full text Cite

Effects of C, Cu, and Be substitutions in superconducting (formula presented)

Journal Article Physical Review B - Condensed Matter and Materials Physics · January 1, 2001 Density functional calculations are used to investigate the effects of partial substitutional alloying of the B site in (formula presented) with C and Be alone and combined with substitution of Mg by Cu. The effect of such substitutions on the electronic s ... Full text Cite

Lattice trapping of cracks in Fe using an interatomic potential derived from experimental data and ab initio calculations

Conference Materials Research Society Symposium - Proceedings · January 1, 2001 A recent approach which combines first-principles and experimental data to produce highly accurate and reliable interatomic potentials is tested for the case of bcc and fcc Fe. The Embedded-Atom-like potential accurately reproduces the basic equilibrium pr ... Cite

Structural stability and lattice defects in copper: Ab initio, tight-binding, and embedded-atom calculations

Journal Article Physical Review B - Condensed Matter and Materials Physics · January 1, 2001 We evaluate the ability of the embedded-atom method (EAM) potentials and the tight-binding (TB) method to predict reliably energies and stability of nonequilibrium structures by taking Cu as a model material. Two EAM potentials are used here. One is constr ... Full text Cite

Predicted properties of NaCaF3

Conference AIP Conference Proceedings · September 12, 2000 More than a decade ago computer simulations based on Gordon-Kirn potentials suggested that NaCaF3 would be a ferroelectric compound if it could be formed experimentally. Recent attempts to form thin films of NaCaF3 using pulsed-laser deposition have prompt ... Full text Cite

Calculation of polarization using a density functional method with localized charge

Journal Article Physical Review Letters · January 24, 2000 A density functional method, which represents the total charge density as a sum of self-consistently determined localized densities, is described. While this approach is generally less accurate than conventional band-structure methods, it offers a relative ... Full text Cite

Energetic, vibrational, and electronic properties of silicon using a nonorthogonal tight-binding model

Journal Article Physical Review B - Condensed Matter and Materials Physics · January 1, 2000 We present calculations of energetic, electronic, and vibrational properties of silicon using a nonorthogonal tight-binding (TB) model derived to fit accurately first-principles calculations. Although it was fit only to a few high-symmetry bulk structures, ... Full text Cite

Electronic structure calculations of PbTe

Journal Article Journal of Physics and Chemistry of Solids · January 1, 2000 The full potential linearized augmented plane wave (LAPW) method was applied to study the electronic structure of the PbTe compound. Calculations of the band structure, density of states, strain energy and total energy as a function of lattice constant hav ... Full text Cite

Tight-binding study of stacking fault energies and the Rice criterion of ductility in the fcc metals

Journal Article Physical Review B - Condensed Matter and Materials Physics · January 1, 2000 We have used the Naval Research Laboratory (NRL) tight-binding (TB) method to calculate the generalized stacking fault energy and the Rice ductility criterion in the fcc metals Al, Cu, Rh, Pd, Ag, Ir, Pt, Au, and Pb. The method works well for all classes o ... Full text Cite

Calculation of electronic, structural, and vibrational properties in alkali halides using a density-functional method with localized densities

Journal Article Physical Review B - Condensed Matter and Materials Physics · January 1, 2000 A recently developed density-functional method based on localized densities is applied to calculate electronic, structural, and vibrational properties of 20 alkali halides with elements lithium through cesium and fluorine through iodine. Properties calcula ... Full text Cite

Occupation-number broadening schemes: Choice of “temperature”

Journal Article Physical Review B - Condensed Matter and Materials Physics · January 1, 2000 Band-structure calculations frequently use an occupation-number broadening method to approximate integrals involving the electronic density of states. The underlying assumptions of these techniques are frequently unstated and can lead to erroneous results. ... Full text Cite

Ab initio calculation of spin gap behavior in CaV4O9

Journal Article Journal of the Physical Society of Japan · January 1, 1999 Second neighbor dominated exchange coupling in CaV4O9 has been obtained from ab initio density functional (DF) calculations. A DF-based self-consistent atomic deformation model reveals that the nearest neighbor coupling is small due to strong cancellation ... Full text Cite

Ab initio based tight-binding hamiltonian for the dissociation of molecules at surfaces

Journal Article Physical Review Letters · January 1, 1999 A tight-binding total-energy (TBTE) method has been developed to interpolate between first-principles results describing the dissociation of molecules at surfaces. The TBTE scheme requires only a relatively small number of ab initio energies as input and g ... Full text Cite

Interatomic potentials for Al and Ni from experimental data and ab initio calculations

Journal Article Materials Research Society Symposium - Proceedings · January 1, 1999 New embedded-atom potentials for Al and Ni have been developed by fitting to both experimental data and the results of ab initio calculations. The ab initio data were obtained in the form of energies of different alternative computer-generated crystalline ... Cite

Interatomic potentials for monoatomic metals from experimental data and ab initio calculations

Journal Article Physical Review B - Condensed Matter and Materials Physics · January 1, 1999 We demonstrate an approach to the development of many-body interatomic potentials for monoatomic metals with improved accuracy and reliability. The functional form of the potentials is that of the embedded-atom method, but the interesting features are as f ... Full text Cite

Second-moment interatomic potential for Cu-Au alloys based on total-energy calculations and its application to molecular-dynamics simulations

Journal Article Journal of Physics Condensed Matter · December 7, 1998 We have evaluated interatomic potentials of Cu, Au and Cu-Au L12 ordered alloys in the framework of the second-moment approximation to the tight-binding theory by fitting to the volume dependence of the total energy of these materials computed by first-pri ... Full text Cite

Application of a tight-binding total-energy method for Al, Ga, and

Journal Article Physical Review B - Condensed Matter and Materials Physics · January 1, 1998 We apply our tight-binding (TB) methodology to the (Formula presented) metals Al, Ga, and In, all of which have distinctive ground states. The results show that this approach works as well for such elements as it does for transition metals. Bulk properties ... Full text Cite

Tight-binding Hamiltonians for carbon and silicon

Conference Materials Research Society Symposium - Proceedings · January 1, 1998 We demonstrate that our tight-binding method - which is based on fitting the energy bands and the total energy of first-principles calculations as a function of volume - can be easily extended to accurately describe carbon and silicon. We present equations ... Cite

The tight-binding method for interpolating first-principles total energy results

Journal Article Journal of Phase Equilibria · January 1, 1997 This paper presents a new tight-binding method for the evaluation of the total energy in solids. The method is calibrated to reproduce a limited set of first-principles results and is able to interpolate between different structures, at a cost which is ord ... Full text Cite

Application of a kohn-sham-like formulation of the self-consistent atomic deformation model

Journal Article Ferroelectrics · January 1, 1997 The self-consistent atomic deformation model is applied to compounds selected to illustrate two important features of the model: 1) The formulation of the potential from a Kohn-Sham like variational treatment of the total energy produces atomic energy leve ... Full text Cite

Equation of state for PdH by a new tight binding approach

Conference Materials Research Society Symposium - Proceedings · December 1, 1996 We present an extension of a newly proposed tight-binding method of calculating total energies and related quantities to the study of binary compounds. As an example, we discuss the equation of state of the palladium-hydrogen system. ... Cite

First-principles calculation of the structure of mercury

Conference Materials Research Society Symposium - Proceedings · December 1, 1996 Mercury has perhaps the strangest behavior of any of the metals. Although the other metals in column IIB have an hcp ground state, mercury's ground state is the body centered tetragonal βHg phase. The most common phase of mercury is the rhombohedral αHg ph ... Cite

Spherical self-consistent atomic deformation model for first-principles energy calculations in ionic crystalline solids

Journal Article Physical Review B - Condensed Matter and Materials Physics · January 1, 1996 We present a first-principles method [called spherical self-consistent atomic deformation (SSCAD)] for calculating the energy per unit cell in ionic crystalline solids. SSCAD is a density-functional method using the local-density approximation (LDA). Wave ... Full text Cite

Applications of a tight-binding total-energy method for transition and noble metals: Elastic constants, vacancies, and surfaces of monatomic metals

Journal Article Physical Review B - Condensed Matter and Materials Physics · January 1, 1996 A recent tight-binding scheme provides a method for extending the results of first-principles calculations to regimes involving (Formula presented)-(Formula presented) atoms in a unit cell. The method uses an analytic set of two-center, nonorthogonal tight ... Full text Cite

Development of a Kohn-Sham like potential in the self-consistent atomic deformation model

Journal Article Journal of Physics and Chemistry of Solids · January 1, 1996 This is a brief description of how to derive the local 'atomic' potentials from the Self-Consistent Atomic Deformation (SCAD) model density functional. Particular attention is paid to the spherically averaged case. ... Full text Cite

A model to compute phase diagrams in oxides with empirical or first-principles energy methods and application to the solubility limits in the CaO-MgO system

Journal Article Journal of the American Ceramic Society · January 1, 1996 The CaO-MgO system is used as a prototype system to evaluate the accuracy of several energy and entropy approximations for predicting solid-state phase diagrams in ionic materials. Configurational disorder between the cations is parameterized with the clus ... Full text Cite

Application of a new tight-binding method for transition metals: Manganese.

Journal Article EPL · September 20, 1995 A new tight-binding total-energy method, which has been shown to accurately predict ground-state properties of transition and noble metals, is applied to manganese, the element with the most complex ground-state structure among the d metals. We show that t ... Full text Cite

Self-consistent potential induced breathing model calculations for longitudinal modes in mgo

Journal Article Ferroelectrics · February 1, 1995 The self-consistent potential-induced breathing model is applied to calculate vibrational modes in MgO using the frozen phonon method. The model gives the frequency difference between longitudinal and transverse optic modes expected for a non-polarizable i ... Full text Cite

Understanding the Nb-Ti-Al system: first principles calculations

Conference Materials Research Society Symposium - Proceedings · January 1, 1995 The discovery of ductile cubic phases in the Nb-Ti-Al system has led to increased study of these high-temperature intermetallics. I have performed first-principles calculations for ordered crystal structures in this system, paying particular attention to t ... Cite

A tight-binding method for the evaluation of the total energy of large systems

Journal Article International Journal of Thermophysics · January 1, 1995 A new tight-binding total energy method, suitable for the description of atomic systems containing hundreds of atoms, is described, The method is applied to the calculation of the vacancy-fonnation energy in the noble metals and several transition metals, ... Full text Cite

Charge transfer effects in knb03 and sodium

Journal Article Ferroelectrics · January 1, 1994 A new self-consistent atomic deformation model for calculating the electronic structure and total energy of condensed matter systems is described. Application of the model to KNb03 suggests a fundamental relation between non-spherical oxygen ion deformatio ... Full text Cite

Tight-binding total-energy method for transition and noble metals

Journal Article Physical Review B · January 1, 1994 A general tight-binding total-energy (TBTE) method is presented that accurately predicts energy differences caused by small perturbations such as those occurring in the evaluation of elastic constants and phonon spectra as well as energy differences from l ... Full text Cite

Properties of ordered intermetallic alloys: first-principles and approximate methods

Journal Article Materials Science and Engineering A · October 1, 1993 Intermetallic alloys which can be made ductile at low temperatures and strong at high temperatures are of great value as materials for current and future high technology applications. Computational physics is a useful tool for locating candidate materials. ... Full text Cite

Phase stability of wüstite at high pressure from first-principles linearized augmented plane-wave calculations

Journal Article Physical Review B · January 1, 1993 We use the local spin-density approximation (LSDA) to investigate the phase stability and physical properties of stoichiometric wüstite at high pressure. Highly converged total-energy calculations are presented for nonmagnetic, ferromagnetic, and antiferro ... Full text Cite

Formation of self-arranging Mo cubes

Journal Article Solid State Communications · January 1, 1993 Previous work suggested that 5 nm Mo cubes, formed from a supersaturated vapor, self-organize in the vapor into larger cubes which are 3 × 3 × 3 arrangements of the smaller cubes. Here new experimental results are described that provide an understanding of ... Full text Cite

Pressure dependence of the elastic moduli in aluminum-rich Al-Li compounds

Journal Article Physical Review B · January 1, 1993 I have carried out numerical first-principles calculations of the pressure dependence of the elastic moduli for several ordered structures in the aluminum-lithium system, specifically fcc Al, fcc and bcc Li, L12Al3Li, and an ordered fcc Al7Li supercell. Th ... Full text Cite

A self consistent atomic deformation model for total energy calculations: Application to ferroelectrics

Journal Article Ferroelectrics · January 1, 1993 An ab initio model for total energy calculations is introduced in which site localized charge densities are determined from the electronic structure of atoms (or ions) in a self consistent overlap potential. In the lowest order expression of the overlap po ... Full text Cite

Electronic structure of ErSi2 and YSi2

Journal Article Physical Review B · January 1, 1992 We present a theoretical and experimental study of erbium and yttrium disilicides. These materials are representative of the trivalent heavy-rare-earth disilicides that can be epitaxially grown on Si(111). The densities of states are obtained using the aug ... Full text Cite

All-electron first-principles supercell total-energy calculation of the vacancy formation energy in aluminium

Journal Article Physica B: Physics of Condensed Matter · June 1, 1991 We use the first-principles all-electron linearized augumented plane-wave (LAPW) method to perform self-consistent total-energy electronic structure calculations for the vacancy formation energy in aluminum in the supercell approximation. The method makes ... Full text Cite

Calculation of energy barriers for physically allowed lattice-invariant strains in aluminum and iridium

Journal Article Physical Review B · January 1, 1991 Total-energy calculations using the full-potential linearized augmented-plane-wave method are employed to determine the energy barrier for physically allowed lattice-invariant strains in iridium (which has a high melting point) and aluminum (for which the ... Full text Cite

First-principles calculation of the elastic moduli of Ni3Al

Journal Article Physical Review B · January 1, 1991 We have computed the elastic constants for Ni3Al in the L12 structure using the full-potential, total-energy linearized augmented-plane-wave method. The results compare extremely well with accepted experimental values. © 1991 The American Physical Society. ... Full text Cite

New low-energy crystal structure for silicon

Journal Article Physical Review Letters · January 1, 1991 A minimum-energy path in strain space has been determined which takes cubic silicon into itself. Energies are computed using the Stillinger-Weber model potential and first-principles total-energy calculations. The energy along this path has an additional m ... Full text Cite

Structural properties of ordered high-melting-temperature intermetallic alloys from first-principles total-energy calculations

Journal Article Physical Review B · January 1, 1990 Intermetallic compounds which are ductile at high temperatures are of great technological interest; however, purely experimental searches for improved intermetallic materials are time consuming and expensive. Theoretical studies can shorten the experimenta ... Full text Cite

Calculated elastic and thermal properties of MgO at high pressures and temperatures

Journal Article Journal of Geophysical Research · January 1, 1990 The pressure and temperature dependence of the thermoelastic properties of MgO were calculated using the potential-induced breathing model. These calculations represent the first attempt to obtain a consistent set of thermodynamic elastic moduli for an oxi ... Full text Cite

Total-energy calculations of solid H, Li, Na, K, Rb, and Cs

Journal Article Physical Review B · January 1, 1990 Augmented-plane-wave calculations within the local-density approximation of the total energy of the solid alkali metals H, Li, Na, K, Rb, and Cs predict that except in Rb at T=0 K the fcc structure is more stable than the bcc, which agrees with experiments ... Full text Cite

Metallization pressure for NaCl in the B2 structure

Journal Article Physical Review B · January 1, 1990 Local-density-approximation results for the electronic structure and elastic properties are reported for NaCl in the B2 structure at large volume compressions. Both linear augmented-plane-wave (LAPW) (with no shape approximations for the potential or charg ... Full text Cite

Zone-center Raman active modes in cubic and hexagonal diamond

Conference Proceedings of SPIE - The International Society for Optical Engineering · July 5, 1989 The recent interest in the growth of thin diamond films has led us to consider the differences between the hexagonal (lonsdaleite) and cubic structures. Both phases have very similar properties, and empirical and theoretical considerations indicate that th ... Full text Cite

Effects of strain on the band structure of diamond

Conference Proceedings of SPIE - The International Society for Optical Engineering · May 18, 1988 There are several extreme properties) of diamond which make it a desireable material for technological applications. Its hardness, which is related to its large elastic moduli, is well known. Less widely recognized are its high thermal conductivity and its ... Full text Cite

Ab initio calculations of static lattice properties for NaCl and a test of the Decker equation of state

Journal Article Physical Review B · January 1, 1988 Calculations of the equilibrium volume and bulk modulus at the equilibrium volume are made for Gordon-Kim based theories of NaCl and used in the Decker approach for calculating the equation of state. Generally the resultant Decker equation of state is in e ... Full text Cite

Raman spectroscopy and theoretical modeling of BeO at high pressure

Journal Article Physical Review B · January 1, 1988 The pressure dependence of the vibrational properties of BeO has been studied by Raman spectroscopy with a diamond-anvil, high-pressure cell. Five fundamental bands in the Raman spectrum were measured at room temperature for both a single crystal compresse ... Full text Cite

Phase transitions and elasticity in zirconia

Journal Article Physica B+C · January 1, 1988 The potential induced breathing (PIB) model is used to calculate equations of state, relative phase stabilities, and elasticity of several different structures of ZrO2. PIB is a non-empirical model for calculation of static and dynamic properties of ionic ... Full text Cite

Elastic constants of NbC and MoN: Instability of B1-MoN

Journal Article Physical Review B · January 1, 1988 Total energies of MoN have been calculated for small strains from the cubic B1 structure to orthorhombic and trigonal structures, and B1-MoN was found to be unstable. To check the reliability of the calculations, we have also calculated the elastic constan ... Full text Cite

Linearized augmented plane wave electronic structure calculations for MgO and CaO

Journal Article Journal of Geophysical Research · January 1, 1988 We present full-potential self-consistent linearized augmented plane wave calculations for the electronic structure and total energy of MgO and CaO, within the local density approximation. Calculated equilibrium properties are in good agreement with experi ... Full text Cite

Theoretical studies of charge relaxation effects on the statics and dynamics of oxides

Journal Article Physics and Chemistry of Minerals · May 1, 1987 Inclusion of spherical charge relaxation in response to the long-range electrostatic potential (potential induced breathing, or PIB) gives improved results for the static and dynamic properties of oxides. PIB is a Gordon-Kim type model, in which the crysta ... Full text Cite

PHASE TRANSITIONS AND ELASTICITY IN ZIRCONIA.

Journal Article Physica B: Physics of Condensed Matter & C: Atomic, Molecular and Plasma Physics, Optics · May 1, 1987 The potential induced breathing (PIB) model is used to calculate equations of state, relative phase stabilities, and elasticity of several different structures of ZrO//2. PIB is a non-empirical model for calculation of static and dynamic properties of ioni ... Cite

Lattice dynamics of the potential-induced breathing model: Phonon dispersion in the alkaline-earth oxides

Journal Article Physical Review B · January 1, 1987 We find the dynamical matrix for the potential-induced breathing (PIB) model for ionic solids, and calculate with no adjustable parameters the phonon-dispersion relations for the alkaline-earth oxides in the B1 structure. Our approach is similar to that of ... Full text Cite

Sodium chloride structural properties: Linearized augmented-plane-wave calculations and pressure calibration

Journal Article Physical Review B · January 1, 1987 Results of calculations, performed to a high degree of accuracy within the local-density approximation (LDA), of the compressive and B1-B2 transition properties of NaCl are presented. Results for the equation of state appear to have significance as a press ... Full text Cite

Angular momentum branching ratios for electron-induced ionization: Atomic and model calculations

Journal Article Physical Review B · January 1, 1987 We present calculations of the matrix elements for electron-induced ionization of core electrons of atoms. We use both self-consistent atomic potentials for accuracy and model potentials to gain physical insight. We pay particular attention to the angular ... Full text Cite

Potential-induced breathing model for the elastic moduli and high-pressure behavior of the cubic alkaline-earth oxides

Journal Article Physical Review B · January 1, 1986 A parameter-free model is presented for the elastic constants and high-pressure behavior of the alkaline-earth oxides MgO, CaO, SrO, and BaO. The model is based on a Gordon-Kim-type calculation for the short-range energy of a crystal. Spherically symmetric ... Full text Cite

Ab initio calculations of the effect of non-rigid ions on the statics and dynamics of oxides

Journal Article Japanese Journal of Applied Physics · January 1, 1985 The potential induced breathing of oxygen ions in a crystal, which plays a major role in explaining the violation of the Cauchy relations and the splitting of the longitudinal and transverse optic frequencies in alkaline earth oxides, is analyzed for BaTiO ... Full text Cite

Beyond the rigid-ion approximation with spherically symmetric ions

Journal Article Physical Review Letters · January 1, 1985 Ab initio calculations show that a spherically symmetric charge relaxation of ions in a crystal, in response to the long-range electrostatic potential, is important for understanding the splitting between longitudinal- and transverse-optic-mode frequencies ... Full text Cite

Relation between shear instability and liquid structure in alkali halides

Journal Article Physical Review Letters · January 1, 1985 Evidence that melting in alkali halides may be caused by shear instability of the solid is obtained by comparison of observed liquid structure, as determined by previously published neutron-scattering data and molecular-dynamics calculations, with that exp ... Full text Cite

Summary Abstract: Pseudodipole Selection Rules for Extended Fine Structure in APS: Calculations and Applications

Journal Article Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films · January 1, 1984 Full text Cite

Static and dynamic properties of one-dimensional disordered magnetic Ising Systems

Journal Article Physical Review B · January 1, 1983 The Ising model with random nearest-neighbor couplings is studied numerically and analytically. The J's are chosen to obey the probability laws P(J)|J|-+ with 0+1, -1J0 for AF, 0J1 for F, and -1J1 for SG. Here F means ferromagnetic, AF indicates antiferrom ... Full text Cite

Beyond the local-density approximation in calculations of ground-state electronic properties

Journal Article Physical Review B · January 1, 1983 Justification, as extensive as is possible, is given for our previously published nonlocal approximation for exchange and correlation. Some new exact limits for atoms and interfaces are obtained, as well as formal quantitative criteria for the validity of ... Full text Cite

Remanent magnetization in a random antiferromagnetic Ising chain

Journal Article Physical Review B · January 1, 1982 We have studied the dynamics of a random antiferromagnetic Ising chain with exchange probability law, P(J)=(1-α)J-α (0<α<1), both analytically and numerically. At low temperatures we find remanent magnetization, decaying slowly (nonexponentially) with time ... Full text Cite

Metastable states in the random antiferromagnetic ising chain

Journal Article Physica B+C · January 1, 1981 We study the kinetic Ising model with random antiferromagnetic exchange, in one dimension. The probability law is suggested on physical grounds to be, P(J)∼J-α(0<α<1, 0 Full text Cite

Easily implementable nonlocal exchange-correlation energy functional

Journal Article Physical Review Letters · January 1, 1981 An exchange-correlation functional for nonuniform electronic systems is developed which provides an easily implementable correction to the local density approximation. It is applied to metallic surface energies, as well as to self-consistent atomic calcula ... Full text Cite

The Van der Waals interaction between an atom and a solid

Journal Article Surface Science · January 1, 1980 Measurements of the scattering of neutral atoms by metal cylinders have indicated a serious discrepancy between theory and experiment for the strength of the long-range Van der Waals interaction. To clarify the content of the theory, we present here a form ... Full text Cite

Comment on "retarded van der Waals force near a metal surface"

Journal Article Physical Review B · January 1, 1980 The corrected microscopic derivation of the retarded van der Waals interaction energy between an atom and a half-infinite, hydrodynamic-model metal slab is presented. The corrected formula is shown to reduce to the well-known local-dielectric result in the ... Full text Cite

Quantum theory of neutral-atom scattering at long range from solid cylinders

Journal Article Physical Review A · January 1, 1980 Qualitative arguments suggest that diffraction effects might be important for the interpretation of the experiments of Shih et al. We derive a tractable quantum theory to describe the scattering of neutral atoms at long range by van der Waals forces from s ... Full text Cite

Theory of neutral atom scattering at long range from metal surfaces

Journal Article Physical Review A · January 1, 1977 We examine possible interactions between neutral atoms and metal surfaces at separations greater than 500, treating the Lifshitz dispersion force, dynamic forces, and fringe fields due to surface roughness. Using the derived interaction energies we compute ... Full text Cite