EXCHANGE ENERGY FROM GAUSSIAN-TYPE BASIS-SETS

Calculations of the Hartree-Fock and local-density approximation exchange energies for all atoms with Z less-than-or-equal-to 18 using the 6-311G** Gaussian-type basis set have been carried out. It is found that this particular basis set reproduces remarkably well both the Hartree-Fock and the local-density approximation exchange energies obtained from higher quality Slater-type orbitals. In addition, the Becke correction to the local-density approximation exchange energy has been studied. The best value of its sole parameter beta, for the 6-311G** basis set, is found to be 0.0051, which differs from its corresponding value of 0.0042 obtained with a Slater-type basis set. Results for other standard Gaussian basis are also reported.