RELATIVISTIC DIRAC-FOCK AND MANY-BODY PERTURBATION CALCULATIONS ON HE, HE-LIKE IONS, NE, AND AR

Relativistic Dirac-Fock and diagrammatic many-body perturbation-theory calculations have been performed on He, several He-like ions, Ne, and Ar. The no-pair Dirac-Coulomb Hamiltonian is taken as the starting point. A solution of the Dirac-Fock equations is obtained by analytic expansion in basis sets of Gaussian-type functions. Many-body perturbation improvements of Coulomb correlation are done to third order. © 1990 The American Physical Society.