Study of the local spin-density functional method for calculating the contact term in atoms

Using various models for the exchange-correlation potential, the spin density of electrons at the nuclei of light atoms (up to Ni) is calculated. The magnitude of the Fermi-contact term is then determined and it is compared with the unrestricted Hartree-Fock calculations and with the available experimental results. It appears that for the alkali metal ions most of the local spin density models give results which are in good agreement with experiment. On the other hand, for atoms, where the existence of contact term is connected with the polarization of the core s-electrons, none of the models yield satisfactory results.The author is indebted to Dr. L.Farkas for valuable discussion concerning the self-consistent-field atomic program.