Amorphous silica at surfaces and interfaces: simulation studies

TL;DR

This paper uses large-scale molecular dynamics simulations to study the structure of silica surfaces and interfaces, comparing classical and ab initio methods, and exploring structural details like ring size distributions inaccessible to experiments.

Contribution

It provides a comparative analysis of classical and ab initio simulations for silica surfaces and interfaces, revealing detailed structural insights.

Findings

Classical MD accurately models silica surface structures.

Ab initio methods validate classical potential accuracy.

Simulations reveal ring size distributions in silica interfaces.

Abstract

The structure of surfaces and interfaces of silica (SiO2) is investigated by large scale molecular dynamics computer simulations. In the case of a free silica surface, the results of a classical molecular dynamics simulation are compared to those of an ab initio method, the Car-Parrinello molecular dynamics. This comparative study allows to check the accuracy of the model potential that underlies the classical simulation. By means of a pure classical MD, the interface between amorphous and crystalline SiO2 is investigated, and as a third example the structure of a silica melt between walls is studied in equilibrium and under shear. We show that in the latter three examples important structural information such as ring size distributions can be gained from the computer simulation that is not accessible in experiments.