Electron Affinities from Equation-of-Motion Frozen Pair-Type Coupled Cluster Methods and Their Dependence on Single Excitations, Molecular Orbitals, and Basis Set Sizes.

ABSTRACT: We introduce a series of alternative electron affinity equation-of-motion frozen-pair coupled cluster (EA-EOM-fpCC) methods for computing electron affinities and open-shell electronic structures. These methods are systematically benchmarked against the reference Δ-CCSD(T) approach and experimental data for a representative molecular data set using natural pair coupled cluster doubles (pCCD) orbitals and various basis set sizes. A comparison to canonical CC methods is also discussed. Additionally, EA-EOM-fpCC results are compared with those derived from the difference between double and single ionization potentials (DIP-EOM-CC and IP-EOM-CC) of dicationic species within the same ground-state fpCC reference framework. Our results demonstrate that frozen-pair approaches significantly reduce c

SUBMITTER: Behjou S 

PROVIDER: S-EPMC12573755 | biostudies-literature | 2025 Oct

REPOSITORIES: biostudies-literature