Abstract
A procedure for obtaining a correlated multiconfiguration Hartree-Fock (MCHF) wave function, similar to the one used for the groud state of Be, is applied to the state. With as a zero-order approximation, a first-order correction is derived which includes the effects of one- and two-electron replacements. Contributions from replacements from a particular pair of electrons were determined separately by a numerical MCHF procedure. The "pair correlation functions" were combined in a final configuration-interaction calculation with 52 configurations. The approximation yielded a total energy of -14.47085 a.u. which accounts for 97.5% of the correlation energy. A further first-order correction improved the correlation energy to 98.0%.
- Received 18 August 1975
DOI:https://doi.org/10.1103/PhysRevA.12.2281
©1975 American Physical Society