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

Abstract

This paper presents an approach to judge the quality of classical interatomic potentials used in molecular dynamics simulations of glasses. The static structure and dynamical properties of amorphous SiO 2 were simulated by classical molecular dynamics using a series of well known interatomic potentials. Theoretical X-ray and neutron structure factors and effective neutron-weighted vibrational density of states of amorphous SiO 2 were computed from the obtained atomistic configurations and quantitatively compared to experimental results. The interatomic potential which best reproduced the experimental X-ray and neutron scattering data severely failed to reproduce the experimental vibrational density of states of amorphous SiO 2 . It is found that only the potential developed by van Beest, Kramer, and van Santen (BKS) was able to adequately reproduce both static structure and dynamical properties of amorphous SiO 2 . Thus, the fact that an interatomic potential is able to properly reproduce static structures of amorphous systems should not be considered as a basis to use this potential to simulate other properties of these systems.

Developing atomistic glass models using potential-free Monte Carlo method: From simple to complex structures

“…The RDF comparison in Figure 6(a) clearly show a good agreement between our model and existing theoretical models as well as the experimental RDF 33 . The first peak at 1.59 Å is due to the Si-O bond length followed by second peak at 2.6 Å due to the O-O distance in tetrahedral motif.…”

In situ formation of rare-earth-doped nanoparticles in a silica matrix from Molecular Dynamics simulations

“…Since silica is a glass former of prime importance, a large variety of interatomic potentials has been designed to investigate its structural and dynamical properties [12][13][14][15][16]. Among them, pairwise potentials with partial charges have been extensively used, since they allow, for a reasonable calculation cost, to model glass samples containing up to several hundreds of thousands atoms during millions of timesteps.…”

Amorphous Silica Slab Models with Variable Surface Roughness and Silanol Density for Use in Simulations of Dynamics and Catalysis

“…Among the fixed-charge force fields, the van Beest, Kramer, and van Santen (BKS) model has been widely used to simulate both crystalline and amorphous silica due to its reliability in predicting both structure and dynamics. − A detailed study carried out by Horbach and Kob of BKS simulations of melting silica found that both static and dynamical properties are in very good agreement with the experiment . Furthermore, BKS is a well-studied force field and has spawned interest in the development of other force fields of a similar potential form. ,, Although BKS was one of the earliest force fields developed for silica simulations, it is robust in predicting the realistic silica structure in both bulk and slab configurations. − It is for these reasons that we use the BKS force field to obtain models for amorphous silica slabs in the present work.…”