Study of electron dispersion curves in liquid alkalis

Abstract

Ashcroft's empty core local model of pseudopotentials in the second-order perturbation theory is used to study the electron dispersion relation, the Fermi energy and deviation in the Fermi energy from free-electron values for the liquid alkali metals. The influence of the six different forms of the local-field correction functions proposed by Hartree, Vashishta–Singwi, Taylor, Ichimaru–Utsumi, Farid et al. and Sarkar et al. on the aforesaid electronic properties is examined explicitly, which reflects the varying effects of screening. The depth of the negative hump in the electron dispersion of liquid alkalis decreases in the order Li→K; except for Rb and Cs, where it increases.