Molecular dynamics study for thermodynamic properties of diatomic fluid (the effect of rotational degree of freedom on properties of fluid)

Abstract

In this paper the effect of rotational degree of freedom on the properties of liquid is analyzed by the Molecular Dynamics (MD) Method. Oxygen is assumed as the liquid and molecules are assumed as both monatomic and diatomic one. Lennard-Jones (LJ) potential is used as the intermolecular potential for monatomic molecule and 2 center Lennard-Jones (2 CLJ) potential is assumed for diatomic molecules. Simulations are performed at various combinations of density and temperature and an Equation of State (EOS) of each liquid is obtained by using these results. The parameters of each potential are determined so that the critical temperature and density are consistent with each other. The properties of liquid such as spinodal line, latent heat, specific heat, thermal conductivity and surface tension are compared with each other and the effect of rotational degree of freedom on the properties of liquid is investigated.