Thermodynamics of tritium.

Abstract

Molecular simulations, using an accurate ab initio-based intermolecular potential, are reported, providing a comprehensive description of the thermodynamic behavior of tritium (T2) at both low (cryogenic) and ambient temperatures and at pressures up to 1 GPa. The study includes the second virial coefficient, vapor-liquid equilibria, energy, enthalpy, heat capacities, isochoric pressure coefficient, isobaric thermal expansion coefficient, isothermal compressibility, Joule-Thomson coefficient, and the speed of sound. The simulations demonstrate the important role of quantum effects on the behavior of these properties. Comparison with the corresponding properties of hydrogen (H2) indicates that there are often large property-dependent differences between the two species. The results confidently extend our knowledge of the thermodynamics of T2 beyond the very scarce amount of available experimental data.