A method for determining elastic properties of solids under pressure is pre
sented, tested and applied to a Monte Carlo study of the Poisson ratios of
binary crystals of hard discs and Lennard-Jones particles in two dimensions
. It is observed that, at a given pressure, the Poisson ratio reaches its m
inimum value for defect-free crystals consisting of identical particles. (C
) 1999 Elsevier Science B.V. All rights reserved.