Silica molecular dynamic force fields-A practical assessment
TF Soules and GH Gilmer and MJ Matthews and JS Stolken and MD Feit, JOURNAL OF NON-CRYSTALLINE SOLIDS, 357, 1564-1573 (2011).
The purpose of this paper is to compare simple and efficient pair-wise force fields for silica glass and assess their applicability for use in large scale molecular dynamic (MD) simulations of laser damage mitigation. A number of pair-wise force fields have been shown to give the random tetrahedral network of silica glass. Further, potentials obtained by fitting quantum mechanical results exhibit many of the properties of silica such as the low thermal expansion and densification. However with these potentials densification is observed at temperatures much higher than experiment. We also show that the thermodynamic melting point of beta-crystobalite similarly occurs at temperatures much higher than observed experimentally. Softer empirical potentials can be constructed that do give liquid properties at experimental temperatures. However in all cases the activation energies for diffusion are lower than the experimental activation energies for viscosity. Published by Elsevier B.V.
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