Isotopic shift in the melting curve of helium: A path integral Monte Carlo study

Abstract
The path integral Monte Carlo method is used to estimate the difference in the melting pressures of 4He and 3He. Thermodynamic and structural properties of both isotopes are also computed using an effective pair potential for the interaction between helium atoms. At low temperature, calculations predict the lighter isotope has the higher melting pressure in almost quantitative agreement with available experimental data. The melting curves of 3He and 4He are found to intersect at T≂100 K.