Quantifying macroscopic ionic transport of a given chemical species in a given material is usually done in terms of ionic diffusivities and/or ionic conductivities (see below), both of which can be evaluated using kMC. Before understanding how a typical kMC simulation progresses, we briefly overview some of the fundamentals of ion transport in solids. The macroscopic measure of mobility of a migrating species is determined by the chemical diffusivity (D c ), which relates to the flux and conductivity of the species through Fick's law , as stated in Eq. 1.