In principle, the E KRA has to be calculated for all possible migration events that can occur in a solid (as the local bonding/coordination environment changes for example). However, calculating E b for all possible hops via NEB calculations is computationally intensive and often impractical. One strategy to circumvent the computational obstacles of NEB calculations is that of the LCE approach. A LCE is normally used to construct a simplified lattice Hamiltonian, which can generate approximate E b quickly (by estimating a E KRA ), based on the local configuration(s) of the moving and non moving species, which is defined in Eq. 9 .