Nuclear contact densities for valence electrons in metals

Abstract

To interpret either magnetic or recoil-free nuclear resonance experiments in metals and alloys, one requires knowledge of the valence electron densities at nuclear sites. An electron diffraction theory is developed which enables such information to be derived in terms of calculable parameters. The latter data are then computed for the monovalent metal ions from potentials previously used with fair success in calculating pseudopotentials. The approach represents a generalization of the method of orthogonalized plane waves, improving on the latter in that it recognizes the dynamical response, via a Schrodinger equation, of valence electrons to the ion core potentials. The chief new feature is a renormalization of the valence electron wave functions due to the attractive core fields and this is qualitatively different from the orthogonal plane wave method which expels charge from the cores. The data are used to account for the observed Knight shifts in lithium and sodium.