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DOE OSTI · 3409811

Linear-Scaling Asymmetric Triples Correction through the Solution of the DLPNO–CCSD Lambda Equations: DLPNO–CCSD(T) Λ

Toth, Elizabeth C. [University of Georgia, Athens, GA (United States)] (ORCID:0009000821812653)·Jiang, Andy [University of Georgia, Athens, GA (United States)] (ORCID:000000026946209X)·Schaefer, III, Henry F. [University of Georgia, Athens, GA (United States)] (ORCID:0000000302522083)
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Abstract

In this research, we derive equations for solving for the stationary points of the DLPNO–CCSD Lagrangian, in the t 1 -transformed formalism introduced earlier and as currently implemented in the P SI 4 quantum chemistry software package. These lambda equations in the local pair natural orbital basis allow for the evaluation of CCSD(T) Λ energetics with linear-scaling computational effort, also known as the asymmetric triples correction. This DLPNO–CCSD(T) Λ method allows for accurate triples contributions to be computed for larger molecules, especially in cases that CCSD(T) is known to be insufficient, such as with multireference systems and bond-breaking systems. We showcase the accuracy of our code on reaction energies, barrier heights, and noncovalent interaction energies. Also showcased are the capabilities of our code by evaluating DLPNO–CCSD(T) Λ energetics on large noncovalent dimers up to 112 atoms, as well as a rhodium catalyst complex containing 66 atoms.

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Toth, Elizabeth C. [University of Georgia, Athens, GA (United States)] (ORCID:0009000821812653), Jiang, Andy [University of Georgia, Athens, GA (United States)] (ORCID:000000026946209X), Schaefer, III, Henry F. [University of Georgia, Athens, GA (United States)] (ORCID:0000000302522083). 2026-07-21. Linear-Scaling Asymmetric Triples Correction through the Solution of the DLPNO–CCSD Lambda Equations: DLPNO–CCSD(T) Λ. https://doi.org/10.1021/acs.jctc.6c00758

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