Asymmetric-Lanczos-Chain-Driven Implementation of Electronic Resonance Convergent Coupled-Cluster Linear Response Theory.

Abstract

We present an implementation of the damped coupled-cluster linear response function based on an asymmetric Lanczos chain algorithm for the hierarchy of coupled-cluster approximations CCS (coupled-cluster singles), CC2 (coupled-cluster singles and approximate doubles), and CCSD (coupled-cluster singles and doubles). Triple corrections to the excitation energies can be included via the CCSDR(3) (coupled-cluster singles and doubles with noniterative-triples-corrected excitation energies) approximation. The performance and some of the potentialities of the approach are investigated in calculations of the visible/ultraviolet absorption spectrum and the dispersion of the real polarizability in near-resonant regions of pyrimidine, the near-edge absorption fine structure (NEXAFS) of ammonia, and the direct determination of the C6 dipole-dipole dispersion coefficient of the benzene dimer.