RELATIVISTIC MULTIREFERENCE MOLLER-PLESSET PERTURBATION-THEORY BASED ON MULTICONFIGURATIONAL DIRAC-FOCK REFERENCE FUNCTIONS

Relativistic multireferencee Moller-Plesset perturbation theory is dev eloped and implemented with analytic basis sets of Gaussian spinors. T he theory takes multiconfigurational Dirac-Fock self-consistent field wavefunctions as reference functions. A procedure is described by whic h to perform multireference second-order Moller-Plesset perturbation t heory calculations for a general class of reference functions construc ted from one-particle Dirac spinors. Multireference perturbation calcu lations are reported for the ground and low-lying excited states of ox ygen-like iron, Fe18+ (Z = 26), and ground-state Zn-0, in which the ne ar degeneracy of a manifold of strongly interacting configurations man dates a multireference treatment. (C) 1998 Elsevier Science B.V. All r ights reserved.