RELATIVISTIC COUPLED-CLUSTER THEORY-BASED ON THE NO-PAIR DIRAC-COULOMB-BREIT HAMILTONIAN - RELATIVISTIC PAIR CORRELATION ENERGIES OF THE XEATOM

Relativistic pair correlation energies of Xe were computed by employin g a recently developed relativistic coupled cluster theory based on th e no-pair Dirac-coulomb-Breit Hamiltonian. The matrix Dirac-Fock-Breit SCF and relativistic coupled cluster calculations were performed by m eans of expansion in basis sets of well-tempered Gaussian spinors. A d etailed study of the pair correlation energies in Xe is performed, in order to investigate the effects of the low-frequency Breit interactio n on the correlation energies of Xe. Nonadditivity of correlation and relativistic (particularly Breit) effects is discussed. (C) 1994 John Wiley & Sons, Inc.