STRUCTURE AND ENERGETICS OF FLUID PARA-HYDROGEN

The properties of neat fluid para-hydrogen from the low temperature li quid lo the subcritical gas (T = 14-25 K) are studied in the isotherma l-isobaric ensemble using the Path Integral Monte Carlo method. The mo lecules are treated as spheres and are assumed to interact via a pair potential. This is a good approximation at low pressures as the anisot ropic part of the potential surface is very small and the molecules ar e in J = 0 at the temperatures of interest. The volume and energy of t he system are determined as a function of temperature and good agreeme nt is found with experiment. In addition, radial distribution function s and structure factors are calculated for the molecular centers of ma ss. The extreme quantum nature of the system is illustrated by compari sons to the corresponding classical model of the system.