A New Self-Consistent Empirical Interatomic Potential Model for Oxides, Silicates, and Silica-Based Glasses

Abstract

A new empirical pairwise potential model for ionic and semi-ionic oxides has been developed. Its transferability and reliability have been demonstrated by testing the potentials toward the prediction of structural and mechanical properties of a wide range of silicates of technological and geological importance. The partial ionic charge model with a Morse function is used, and it allows the modeling of the quenching of melts, silicate glasses, and inorganic crystals at high-pressure and high-temperature conditions. The results obtained by molecular dynamics and free energy calculations are discussed in relation to the prediction of structural and mechanical properties of a series of soda lime silicate glasses.

Selecting reliable interatomic potentials for classical molecular dynamics simulations of glasses: The case of amorphous SiO2

“…The absence of any unique approach to judge the quality of an interatomic potential by classical 5 molecular dynamics users can lead to unreliable results and conclusions. Thus, the way the quality of an interatomic 6 potential is judged for a particular molecular dynamics study is an important issue that needs to be properly addressed. 7 The majority of molecular dynamics users do not usually develop their own classical interatomic potentials.…”

“…The methodologies and approaches used 31 in this study are, however, applicable to any other amorphous system. We considered the following well-known Cormack et al [5], and (vi) PMMCS, developed by Pedone et al [6]. Acronyms of the potentials names stand for the 35 initials of the authors who have developed or further refined these potentials.…”

“…In the following we quantitatively evaluate the ability of classical molecular dynamics simulations based on the 142 TTAM [1], BKS [2], T [3], FB [4], DC [5], and PMMCS [6] interatomic pair potentials to reproduce both static 143 structure and dynamical properties of amorphous SiO 2 . In Table 2 we report the experimental and classical molecu- est agreement with experimental results would result in R-factor of one.…”

“…In Table 2 the quality rank of the different 153 interatomic potentials are reported in square brackets. 1.00 [6] From the quality indexes reported in Table 2 it can be seen that from static structure point of view the PMMCS 155 interatomic potential has the highest quality. On contrary, the FB pair interatomic potential has the lowest ability 156 to reproduce the static structure of amorphous SiO 2 .…”

“…Table 3. Self-diffusion coefficients D, heat capacity at constant pressure c p , and isothermal compressibility β of amorphous SiO 2 derived from molecular dynamics simulations using the TTAM [1], BKS [2], T [3], FB [4], DC [5], and PMMCS [6] interatomic pair potentials. The selfdiffusion coefficients of silicon and oxygen and their ratio are reported at both room temperature and 1000 K. Experimental results of the heat capacity at constant pressure [21] and isothermal compressibility [20] First we comment on the self-diffusion results.…”