Optimal Orbital Selection for Full Configuration Interaction (OptOrbFCI): Pursuing the Basis Set Limit under a Budget.

Journal Article (Journal Article)

Full configuration interaction (FCI) solvers are limited to small basis sets due to their expensive computational costs. An optimal orbital selection for FCI (OptOrbFCI) is proposed to boost the power of existing FCI solvers to pursue the basis set limit under a computational budget. The optimization problem coincides with that of the complete active space SCF method (CASSCF), while OptOrbFCI is algorithmically quite different. OptOrbFCI effectively finds an optimal rotation matrix via solving a constrained optimization problem directly to compress the orbitals of large basis sets to one with a manageable size, conducts FCI calculations only on rotated orbital sets, and produces a variational ground-state energy and its wave function. Coupled with coordinate descent full configuration interaction (CDFCI), we demonstrate the efficiency and accuracy of the method on the carbon dimer and nitrogen dimer under basis sets up to cc-pV5Z. We also benchmark the binding curve of the nitrogen dimer under the cc-pVQZ basis set with 28 selected orbitals, which provide consistently lower ground-state energies than the FCI results under the cc-pVDZ basis set. The dissociation energy in this case is found to be of higher accuracy.

Full Text

Duke Authors

Cited Authors

  • Li, Y; Lu, J

Published Date

  • October 2020

Published In

Volume / Issue

  • 16 / 10

Start / End Page

  • 6207 - 6221

PubMed ID

  • 32786901

Pubmed Central ID

  • 32786901

Electronic International Standard Serial Number (EISSN)

  • 1549-9626

International Standard Serial Number (ISSN)

  • 1549-9618

Digital Object Identifier (DOI)

  • 10.1021/acs.jctc.0c00613

Language

  • eng