COMPUTATION OF 2ND-ORDER CORRELATION ENERGIES USING A FINITE-ELEMENT METHOD FOR ATOMS WITH D-ELECTRONS

A polynomial version finite element method has been applied, within th e Moller-Plesset theory, to calculate second-order pair and total corr elation energies for several closed-shell systems with d electrons: Zn , Zn2+ and Cu+. We have employed basis sets including functions up to l(max) = 12, which are so close to completeness that radial extrapolat ion is not necessary, and produce extremely accurate results. The fina l values are compared with the most accurate values found in the liter ature, which were calculated using Slater basis functions. The agreeme nt is relatively good in the case of the total correlation energies bu t not in some details of the electron correlation.