Multiconfiguration Hartree-Fock method and many-body perturbation theory: A unified approach

Publisher Website
Google Scholar
Abstract
The multiconfiguration Hartree-Fock theory and many-body perturbation theory are combined in a calculation of the correlation energy of the ground state of the neutral beryllium atom. For this purpose the two-component Be multiconfiguration Hartree-Fock wave function is treated as a reference state and perturbation theory is used to systematically improve upon the accuracy of this function. The correlation energy of each pair of occupied orbitals is determined by solving numerically a coupled set of two-particle inhomogeneous equations. A detailed comparison is made with other beryllium calculations.