الملخص
Fixed temperature molecular dynamics simulations have been performed at different temperatures ranging from 300 K to 1400 with the objective of establishing and validating the temperature dependent structural and thermodynamic properties. The simulations were carried out in NVT ensemble using Lennard-Jones pair potential (in the NVT (or canonical) ensemble, the number of atoms (N), volume of the system (V) and the system temperature (T) are the independent variables and are kept constant. While it is easy to specify in a molecular dynamics (MD) simulation that the number of atoms and system volume must be kept constant, the temperature control is more involved). Radial distribution functions (RDF) have been calculated. RDF peaks are found to broaden and decrease in heights with increasing temperature, reflecting enhanced atomic motions. Energy temperature graph does not show any break, however a break in the specific heat curve and a λ type transition are observed indicating second order phase transition. Mean Square Displacement (MSD) for Zn and S atoms have been calculated separately and almost identical graphs were obtained. The MSD curve exhibits the existence of maximum disorder at 1100 K and 1400 K which indicates phase transformations...
