INCLUSION OF HARTREE-FOCK EXCHANGE IN THE DENSITY-FUNCTIONAL APPROACH - BENCHMARK COMPUTATIONS FOR DIATOMIC-MOLECULES CONTAINING H, B, C, N, O, AND F ATOMS

Geometries, stabilities and spectroscopic properties of diatomic molecules containing H, B, C, N, 0, and F atoms have been studied using extended basis sets with recently introduced density functionals incorporating gradient corrections and some Hartree-Fock Fock exchange. The errors on all the properties considered in the present study are significantly reduced with respect to standard density functionals and approach the level of the most sophisticated post-Hartree-Fock procedures. These findings, together with the favourable scaling of the computation time with the number of electrons, give further support to the perspectives of the density functional approach as a promising theoretical tool for the study of large, chemically significant species.