The dynamic properties of ions in the melt were studied by using molecular dynamics methods. The diffusion constant, ionic conductivity and velocity autocorrelation function were calculated for various pressures and temperatures. It was found that the simulated ionic conductivities were close to the experimental values, and exhibited an increase with temperature. The diffusion constant went through a maximum at about 10GPa, and was closely related to a marked shift in the coordination number of the Si ion. The velocity autocorrelation function and its spectra were calculated by using the memory-function method. These compared well with the molecular dynamics results.

Ion Motion in SiO2 Melt. S.P.Huang, F.Yoshida, J.You, G.Jiang, K.Xu: Journal of Physics - Condensed Matter, 1999, 11[28], 5429-36