An interaction potential for barium sulfide: A molecular dynamics study

Structural, dynamical and thermodynamic properties of barium sulfide, as well as the structural transformation induced by pressure, are investigated in a molecular dynamics simulation based on an effective two-body interatomic potential. The two-body interatomic potential proposed for BaS is made up of steric repulsions, Coulomb interactions due to charge transfer, charge-induced dipole attractions due to the electronic polarizability and van der Waals attraction. The stability of the most stable phases of this compound, the vibrational density of states, heat capacity as a function of temperature, melting and recrystallization, as well as the structural phase transformation induced by pressure, are correctly described. It is shown that this phase transformation depends strongly on the temperature and crystallinity of the material. The simulated results are compared with experimental observations and other calculations reported in the literature.