Correlation between microstructure and density of Germania melts: insight from molecular dynamics simulation

Molecular dynamics simulation of Germania (GeO 2 ) melt at different densities has been carried out to investigate the microstructural transformation, polyamorphism and structural heterogeneity. The structure of GeO 2 is studied by GeO x basic units and their cluster. The simulation results show that the structure of GeO 2 is formed by GeO x structural units linking to each other via with corner-sharing, edge-sharing, face-sharing bond. The polyamorphism and structural heterogeneity in GeO 2 depend on fraction of GeO x units and distribution of GeO x cluster. The relationship between structure and density is analyzed via the change of pair radial distribution function (PRDF). The edge- and face-sharing bonds are responsible for the first peak splitting of Ge–Ge PRDF. The location of the two first sub-peaks of Ge–Ge PRDF corresponds to the length of edge- and corner-sharing bonds.