Simplified Interpretation of Transport in Disordered Inorganic Ion Conductors from Vacancy Dynamics

Ion transport in structurally disordered inorganic ion conductors can be interpreted as cation jumps between sites provided by the network. Because of the small number of vacant sites and strong intercationic Coulomb interaction, their dynamics is very complex. Based on molecular dynamics simulations we recast the ion dynamics via a sophisticated mapping procedure into the corresponding vacancy dynamics. Remarkably, in this framework, the transport can be interpreted to a very good approximation as a noninteracting single-particle processes. In particular, the macroscopic conductivity can be directly obtained from the local vacancy hopping rates.