A quantum mechanical discussion of the cohesive forces and thermal expansion coefficients of the alkali metals

Abstract

1—The first successful calculation of the cohesive forces in metals was made by Wigner and his collaborators, who have obtained wave functions for electrons in metallic Li and Na by numerical integration. The purpose of this paper is twofold: firstly, we shall show that good approximate wave functions for the alkali metals can be obtained by simple analytical methods, the results agreeing well with those of the more exact calculations and with experiment; and secondly, we shall use these wave functions to calculate for the alkali metals the thermal expansion coefficient, a quantity which has not previously been derived from the theory. 2—Following Wigner and Seitz, we surround each atom by a polyhedron, which we replace by a sphere (the atomic sphere) of radius r 1 defined by 4π/3 r 1 3 = atomic volume.