Coupling of ion and network dynamics in lithium silicate glasses: a computer study.

We present a detailed analysis of the ion hopping dynamics and the related nearby oxygen dynamics in a lithium metasilicate glass via molecular dynamics simulation. For this purpose we have developed numerical techniques to identify ion hops and to sample and average dynamic information of the particles involved. This leads to an instructive insight into the microscopic interplay of ions and network. It turns out that the cooperative dynamics of lithium and oxygen can be characterized as a sliding door mechanism. It is rationalized why the local network fluctuations are of utmost importance for the lithium dynamics.