A Lattice Model of Liquid Helium, II

Abstract
The partition function of the lattice model of liquid helium introduced in the preceding paper is calculated by making use of the Kikuchi's approximation. Setting two parameters, the effective mass m = 1/7m0 (m0 is the mass of He atom), and the lattice spacing d = 3.1Å, an excellent agreement of the density dependence of λ-temperature with experiment is obtained. The general trend of other thermodynamical quantities calculated in this paper is in good accordance with the observation.