Many-body perturbation theory applied to Be+ ion

Abstract

The Bruecner–Goldstone many‐body perturbation theory has been applied to the study of the electron correlation problem of atomic beryllium ion in its ground‐state ²S. An orthonormal complete set is generated from V^N–1 potential. In the present calculation, the final correlation energy is −0.0510 a.u., as compared with −0.0477 a.u. from the estimate made by Weiss. The l dependence of the factors, a and b, appearing in the geometric sum approximation is also investigated, and is found to be independent of it in present calculation.