From an atomistic point of view, ion migration in crystalline materials corresponds to the hopping of the charge carriers from one stable interstitial position to the next equivalent position hindered by an activation barrier. As the energetics play a crucial role in understanding these dynamics in battery materials, Density Functional Theory (DFT) calculations have become the method of choice for their reliable determination . Still, in order to identify the position and height of the activation barrier, the energy minimum path between two equivalent sites needs to be identified, for example by transition state search routines . The highest point along this path corresponds to the migration barrier. Together with the vibrational frequencies at the initial and the transition state, the kinetic rate constant for the hopping over the barrier can be derived using transition state theory .