Thermodynamical and structural properties of neon in the liquid and supercritical states obtained from ab initio calculations and molecular dynamics simulations

Abstract

Thermodynamical and structural properties including the equation of state, the second virial coefficient, the enthalpy and internal energy, the molar heat capacity, the speed of sound, the thermal expansion and pressure coefficients, the compressibility, and the pair distribution function are calculated in an ab initio approach for supercritical and liquid neon. The neon dimer potential energy curve has been obtained previously from ab initio calculations and is applied in classical molecular dynamics simulations. Care was taken to eliminate all possible errors thus reducing the remaining error in the supercritical state at higher temperatures to two sources, namely, the inaccuracies in the quantum chemical potential curve and the two particle approximation in the simulation. At lower temperatures, there is in addition an error due to the classical simulation. The calculated properties will be used as benchmarks in future work to investigate the influence of an improved potential curve and of an inclusion of the three particle potential in the simulation.