Structure and dynamics of molten AgCl: the inclusion of induced polarization

Abstract

Three sets of molecular dynamics simulations have been carried out to study the static structure and transport properties of molten AgCl at 1073 K. The first uses the Vashishta-Rahman rigid-ion potential (R-VR). The other two are polarizable ion potentials, which consist of the Vashishta-Rahman (P-VR) or the Born-Mayer (P-BM) rigid-ion potentials to which the anion-induced dipole polarization contributions are added. Both polarized model potentials reproduce well the main features of the structure of molten AgCl, including the characteristic three-peak feature present in the experimental broad principal peak of its total structure factor; this is not present in the R-VR simulations. The two polarized model potentials differ significantly in the way they account for the transport properties of the melt, by the mean square displacements, the velocity correlation functions, self-diffusion coefficients, or the ionic conductivity. In the case of the latter, the experimental result (ó ) 4.7 (¿âcm)-1) is bracketed between the R-VR (ó ) 5.8 (¿âcm)-1) and the P-VR (ó ) 4.0 (¿âcm)-1) values, with the P-BM value (ó ) 1.3 (¿âcm)-1) significantly lower.