Relativistic Electron Correlation Theory

Abstract

Accurate determination of relativistic correlation corrections, nondynamic and dynamic, is crucial to the prediction of term energy separations and transition probabilities of heavy atom systems. Relativistic and correlation effects are strongly intertwined and play an essential role in the electronic structure of many-electron systems and they must be approached with a relativistic many-body theory that simultaneously account for relativity and electron correlation. Relativistic dynamic correlation energies of the ground-state noble gas atoms, Ne through Rn, systems in which quasidegeneracy is absent, are computed by means of a single-configuration Dirac-Fock-Breit self-consistent field and relativistic Moller-Plesset perturbation theory based on the no-pair Dirac-Coulomb-Breit Hamiltonian. Nondynamic and dynamic correlation energies of Zn and Pb are computed by means of a recently developed relativistic multireference many-body perturbation theory. These are among the systems in which quasidegeneracy in both the ground and excited states mandate multireference perturbation theory. The contribution to transition energies of the Coulomb and Breit correlation corrections in Zn and Pb are analyzed in detail.