A list of probabilities (Γ m ) is generated for all possible migrating paths (m) available for all mobile ions in the simulation box. This list also includes hops which may not be feasible. For example, if both the initial and final sites of a migration path are occupied by an atom (instead of one of the sites being vacant), the value of Γ m is set to 0. The hopping probability (Γ) for each migration event is calculated using the transition state theory via Eq. 11.