RADIAL LIMIT OF LITHIUM REVISITED

Configuration interaction (CI) calculations are carried out for the gr ound state of lithium using a thoroughly optimized basis set of s-type Slater functions. They establish that the radial limit of the nonrela tivistic energy of the ground S-2 state of lithium is no higher than - 7.448666443E(h). Thus, radial correlation accounts for 35.2% of the to tal correlation energy. The radial CI wave function predicts a signifi cantly more accurate Fermi contact parameter than the Hartree-Fock wav e function. However, the imbalanced treatment of electron correlation in the radial CI wave function leads to an excessively diffuse electro n density that is worse than that of the Hartree-Fock wave function. ( C) 1997 John Wiley & Sons, Inc.