ISOTOPE EFFECT ON THE MELTING OF PARA-HYDROGEN AND ORTHO-DEUTERIUM CLUSTERS

Path integral Monte Carlo calculations have been used to investigate the isotope effect on the "melting" of small clusters of para-hydrogen (p-H-2) and ortho-deuterium (o-D2). While clusters of (o-D2)N with N = 13 and 55 exhibit a quantum-lipid --> quantum-solid "freezing" transition in a temperature regime where the effects of Bose statistics are unimportant, the corresponding (p-H-2)N clusters do not.