ELECTRON DISPERSION IN LIQUID ALKALI-METALS

A local pseudopotential in the second-order perturbation theory is use d to study the electron dispersion relation, the Fermi energy and devi ation in the Fermi energy from free electron value for the liquid alka li metals. The influence of the five different forms of the local fiel d correction functions on the aforesaid electronic properties is exami ned explicitly, which reflects the varying effects of screening. The d epth of the first negative hump in the electron dispersion curves of t he liquid alkali metals increases in the order Na, K, Rb, Cs.