Energy differences using an accurate local density functional

The accurate local spin density (LSD) functional of Vosko, Wilk, and Nusair, based on electron gas correlation energies of Ceperley and Alder, has been used to calculate interconfigurational energies for atoms and binding energies for first row diatomic molecules. The description of ionization and sp-transfer energies in first row atoms and of low-lying states in B2 and C2 are better than those obtained with earlier parametrizations. Interconfigurational energies in iron series atoms are essentially unchanged from values obtained using previous electron gas parametrizations. Spin–flip energies using the Xα approximation are uniformly inferior to those given by LSD.