Density functional approximation for the quasiparticle properties of simple metals. II. Application to Li, Rb and Cs

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Abstract
For pt.I see ibid., vol.10, no.8, p.1719 (1980). Results are presented for the Fermi surfaces and quasiparticle velocities of Li, Rb and Cs implied by three separate approximations for the mass operator. Comparison with experiment indicates that a non-local energy-dependent mass operator, previously suggested in the context of the density functional formalism, is a good approximation for simple metals. Comparison with the more commonly used local mass operator approximations show that a more accurate description of many-body effects results in a reduction of Fermi surface distortions and quasiparticle mass anisotropies by a factor of around two. In addition, a substantial electron-electron renormalisation of the average quasiparticle mass is predicted in Li and Cs despite the absence of a large renormalisation in the uniform electron gas.