Role of quantum corrections to the kinetic energy and three-body interactions on the thermodynamic properties of neon

Abstract

Molecular simulations are reported for the thermodynamic properties of Ne at temperatures between 30 and 300 K and pressures up to 100 MPa using an intermolecular potential that combines ab initio two-body, three-body, and quantum terms. Quantum corrections to the kinetic energy (QCKE) are also applied to the simulation data. Three-body interactions make important contributions to the pressure–volume–temperature behavior, enthalpy, heat capacity, isothermal compressibility, isochoric pressure coefficient, and isobaric thermal expansion coefficient of Ne. In particular, three-body interactions are required to correctly determine the volume and greatly improve the accuracy of enthalpy, isochoric pressure coefficient, and isobaric thermal expansion coefficient. QCKE also make an important contribution to the properties of Ne that has not been previously recognized. The addition of QCKE means that the caloric thermodynamic properties of Ne can often be determined a priori to an accuracy comparable to that of the reference data.