MONTE-CARLO CALCULATION OF INTEGRAL ENTROPY FROM DIFFUSE-SCATTERING INTENSITY

Abstract

A theory by which the integral entropy may be calculated from the diffuse scattering intensity was proposed by Hoffman (Metall. Trans. 3, 3231 (1972)). In this paper the Hoffman theory is tested by Monte Carlo computer simulation. Several lattices of two and three dimensions were considered in this investigation. The results from the Hoffman theory are compared with those from the exact solution and from the Meirovitch local state method. It is found that the Hoffman theory works well in the high temperature range. In the low temperature range, however, the theory gives lower values of the integral entropy than the other reliable methods. At temperatures close to the critical temperature, it is even not possible to evaluate the entropy from the Hoffman theory, since the diffuse scattering intensity is negative at certain wave vector points.