Thermodynamics and Molecular Dynamic Simulations of Three-phase Equilibrium in Argon (V6)

Very simplified equations of state (EOS) are proposed for a system involving argon and consisting of a perfect solid and a perfect liquid composed of single spherical molecules in which Lennard–Jones interactions are assumed. Molecular dynamics simulations of this system were performed to determine the temperature and density dependencies of the internal energy and pressure and the supercooled liquid state was also examined. The internal energy and pressure were found to be almost linear as functions of temperature at a fixed volume. The density dependencies of coefficients for pressure and the internal energy are written by linear functions of number density for simplicity and for ease of use.