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arXiv · 2410.13001

Many-Body Basis Set Amelioration Method for Incremental Full Configuration Interaction

Jeffrey P Hatch·Alan E Rask·Duy-Khoi Dang·Paul M Zimmerman
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Abstract

Incremental full configuration interaction (iFCI) is polynomial-cost approach to the FCI limit of electronic structure. This article introduces the many-body basis set amelioration (MBBSA) method, which is designed to allow iFCI to be applicable to larger atomic orbital basis sets. MBBSA uses a series of inexpensive iFCI calculations to approximate the correlation energy that would be found using a more expensive, highly accurate iFCI calculation. When compared to standard iFCI computations on smaller molecules in triple-zeta and larger basis sets, MBBSA provides approximations to total and relative energies within chemical accuracy. MBBSA yields cost savings of between 60 and 92% when compared to standard iFCI calculations, with larger systems having increased savings. Tests of MBBSA on two reactions that involve highly correlated systems, the automerization of cyclobutadiene and a Criegee intermediate reaction, show that MBBSA has practical utility for studying realistic chemistries.

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Jeffrey P Hatch, Alan E Rask, Duy-Khoi Dang, Paul M Zimmerman. 2024-10-16. Many-Body Basis Set Amelioration Method for Incremental Full Configuration Interaction. https://arxiv.org/abs/2410.13001

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