Numerical Hartree-Fock-Slater Calculations on Diatomic Molecules

Abstract

<p>A completely numerical method has been developed for the calculation of Hartree-Fock-Slater wave functions in diatomic systems. The method is numerical in the sense that no LCAO basis sets are employed. All molecular functions are represented by cubic spline interpolants on a two-dimensional discrete mesh in prolate spheroidal coordinates. The method is mathematically simple, and numerical accuracy is very easily controlled by adjusting the number of mesh points. Furthermore, it is easily applied to other local exchange-correlation theories beyond the Hartree-Fock-Slater approximation.</p> <p>Calculations on the molecules B₂, C₂, N₂, CO, O₂ and F₂ have been carried out in order to compare dissociation energies, bond lengths, vibrational frequencies and quadrupole (or dipole) moments with recently reported LCAO results, and with experiment. These calculations indicate that the present numerical method works very nicely for the molecules considered, and also that the Hartree-Fock-Slater theory describes molecular systems remarkably well.</p>