Calculations of the spin susceptibilities and their volume dependence for Li, Na, and K

For a range of lattice parameters the Kohn–Sham equations were solved self-consistently in the muffin-tin and local spin density approximations for Li, Na, and K metals. The solutions were used to evaluate the spin susceptibilities χ p via the variational principle of Vosko and Perdew for two choices of χ h , the spin susceptibility of an interacting homogeneous electron gas: (i) the RPA result due to Shastry, and (ii) the Keiser and Wu (KW) result. For Li and K the volume dependence and absolute values of χ p are in excellent agreement with experiment whereas for Na the RPA seems to be better. Calculations for K over an extended range of volumes show that non-linearity in χ p sets in for V/V 0 = 0.9.