Journal of Chemical Physics, Vol.117, No.22, 9983-9990, 2002
Orbital nonrelaxed coupled cluster singles and doubles with perturbative triples corrections calculations of first-order one-electron properties
The calculation of first-order one-electron molecular properties is discussed for an orbital nonrelaxed CCSD(T) (coupled cluster singles and doubles with perturbative triples corrections) wave function model. The conventional CCSD(T) triples amplitude equations have been generalized to contain terms that depend explicitly on the perturbation to compensate for the fact that the Hartree-Fock molecular orbitals are not allowed to relax. Results of sample calculations are presented, including the molecular electric quadrupole moment of benzene in the d-aug-cc-pVTZ basis set, which contains 564 contracted basis functions.