Density functional theory and molecular bonding. I. First-row diatomic molecules

The density functional equations of Hohenberg, Kohn, and Sham (HKS) are solved self-consistently for simple molecules using a method described originally by Andersen and Woolley. Spectroscopic constants, calculated for B2, N2, O2, F2, CO, and BF and for the four lowest lying states of C2, are in good agreement with experiment. Results are consistently better than Hartree–Fock and comparable with those of configuration interaction calculations.