Liquid water simulations with the density fragment interaction approach.

Published

Journal Article

We reformulate the density fragment interaction (DFI) approach [Fujimoto and Yang, J. Chem. Phys., 2008, 129, 054102.] to achieve linear-scaling quantum mechanical calculations for large molecular systems. Two key approximations are developed to improve the efficiency of the DFI approach and thus enable the calculations for large molecules: the electrostatic interactions between fragments are computed efficiently by means of polarizable electrostatic-potential-fitted atomic charges; and frozen fragment pseudopotentials, similar to the effective fragment potentials that can be fitted from interactions between small molecules, are employed to take into account the Pauli repulsion effect among fragments. Our reformulated and parallelized DFI method demonstrates excellent parallel performance based on the benchmarks for the system of 256 water molecules. Molecular dynamics simulations for the structural properties of liquid water also show a qualitatively good agreement with experimental measurements including the heat capacity, binding energy per water molecule, and the radial distribution functions of atomic pairs of O-O, O-H, and H-H. With this approach, large-scale quantum mechanical simulations for water and other liquids become feasible.

Full Text

Duke Authors

Cited Authors

  • Hu, X; Jin, Y; Zeng, X; Hu, H; Yang, W

Published Date

  • June 2012

Published In

Volume / Issue

  • 14 / 21

Start / End Page

  • 7700 - 7709

PubMed ID

  • 22466097

Pubmed Central ID

  • 22466097

Electronic International Standard Serial Number (EISSN)

  • 1463-9084

International Standard Serial Number (ISSN)

  • 1463-9076

Digital Object Identifier (DOI)

  • 10.1039/c2cp23714h

Language

  • eng