Computer simulations of SiO2 and GeO2
Classical Molecular Dynamics (MD) simulations are used to study structural and dynamic properties of amorphous germania (GeO2) in comparison to those of silica (SiO2). The total structure factor, as obtained from these simulations, is in very good agreement with that of neutron scattering experiments, both for germania and silica. The tetrahedral network structure in silica and germania leads to a prepeak in the structure factor that appears at slightly smaller wavenumbers in GeO2 than in SiO2. At high temperatures the diffusion constants are very similar in both systems whereas at low temperatures diffusion is significantly faster in germania than in silica. We also outline the strategy for the development of a potential for SiO2-GeO2 mixtures by means of Car-Parrinello MD.
KeywordsClassical Molecular Dynamics Lithium Silicate Partial Structure Factor Sodium Disilicate Total Structure Factor
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