# Accession Number:

## AD0630167

# Title:

## EXACT SOLUTIONS FOR A SEMI-INFINITE SQUARE LATTICE GAS,

# Descriptive Note:

# Corporate Author:

## HARRY DIAMOND LABS WASHINGTON D C

# Personal Author(s):

# Report Date:

## 1966-02-01

# Pagination or Media Count:

## 24.0

# 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

# Subject Categories:

- Physical Chemistry