Accession Number : AD0630167

Title :   EXACT SOLUTIONS FOR A SEMI-INFINITE SQUARE LATTICE GAS,

Corporate Author : HARRY DIAMOND LABS WASHINGTON D C

Personal Author(s) : Karayianis,N. ; Morrison,C. A. ; Wortman,D. E.

Report Date : FEB 1966

Pagination or Media Count : 24

Abstract : The problem of a two-dimensional lattice gad with nearest neighbor infinite repulsion is considered by obtaining exact solutions for a sequence of semi-infinite spaces. The exact solutions are obtained for M x infinity spaces with 2 < or = M < or = 14 in even steps, and although there are no phase transitions in these spaces, a criterion for the point of 'closet approach' to a phase transition is established. The values of the thermodynamic variables evaluated at this point for each M are extrapolated to obtain the properties of the two-dimensionally infinite space. The data indicate a third-order phase transition occurring with probably infinite compressibility at an activity z = 3.799, a density = 0.7356, and a pressure = 0.7914. The density is obtained by a rigorous differentiation of the secular determinant that determines the value of the pressure for a given z, thus securing the accuracy of the calculations and enabling the extrapolated values of the thermodynamic variables to be estimated with good precision. (Author)

Descriptors :   (*STATISTICAL MECHANICS, GASES), PHASE STUDIES, THERMODYNAMICS, SEQUENCES(MATHEMATICS)

Subject Categories : Physical Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE