New optimization scheme to obtain interaction potentials for oxide glasses

Siddharth Sundararaman (1, 2) , Liping Huang (1) , Simona Ispas (2) , Walter Kob (2)

1 RPI - Rensselaer Polytechnic Institute
2 L2C - Laboratoire Charles Coulomb

We propose a new scheme to parameterize effective potentials that can be used to simulate atomic systems such as oxide glasses. As input data for the optimization, we use the radial distribution functions of the liquid and the vibrational density of state of the glass, both obtained from ab initio simulations, as well as experimental data on the pressure dependence of the density of the glass. For the case of silica, we find that this new scheme facilitates finding pair potentials that are significantly more accurate than the previous ones even if the functional form is the same, thus demonstrating that even simple two-body potentials can be superior to more complex three-body potentials. We have tested the new potential by calculating the pressure dependence of the elastic moduli and found a good agreement with the corresponding experimental data.

Domaines: Chimie-Physique [physics.chem-ph]; Matière Condensée [cond-mat]

Siddharth Sundararaman, Liping Huang, Simona Ispas, Walter Kob. New optimization scheme to obtain interaction potentials for oxide glasses. Journal of Chemical Physics, 2018, 148, pp.194504. ⟨10.1063/1.5023707⟩. ⟨hal-01806569⟩