Occurrence and Impact of Electric-Field-Induced Discontinuities in Correlation Energies from Localized Pair-Natural-Orbital Methods.

ABSTRACT: We report an investigation of discontinuities in the correlation energy produced by external static electric fields within the local pair-natural-orbital coupled-cluster singles and doubles (LPNO-CCSD) method. Such discontinuities arise as a result of variations in both the dimensions and character of the pairwise virtual-orbital domains resulting from changes in the strength of the field. Using several small-molecule test cases - water, fluoroethylene, hypofluorous acid and cis-1,3-butadiene we observe that, although the discontinuities in the correlation energy are small (typically 1 μE_h), they can yield substantial errors in higher-order electric-field-dependent properties computed using finite-difference techniques. For the static hyperpolarizability (th

SUBMITTER: Madriaga JP 

PROVIDER: S-EPMC12581137 | biostudies-literature | 2025 Oct

REPOSITORIES: biostudies-literature