SHEAR MODULUS OF FLUIDS AND SOLIDS

The shear modulus tensor, whose components are Voigt elastic moduli, i s expressed as an N-particle average. The Born-Green and the fluctuati on contributions are identified and, when possible, also expressed in terms of integrals over the pair-correlation function. Symmetry consid erations are invoked for systems of spherical particles in both isotro pic and cubic states. Results from molecular dynamics simulations are presented for particles with a purely repulsive Lennard-Jones interact ion. Shear and bulk moduli are displayed graphically as functions of t he density for fluid and cubic crystalline states. The shear modulus p roves to be a good indicator for the fluid-solid phase transition.