(Step 1): Graph encoding. A graph is constructed for a given symmetrically distinct migration path that consists of N + n nodes for the relaxed host crystal structure's N crystallographic sites, V = {v 1 , . . . , v N }, and the migration path's n images, P = {v p1 , . . . , v pn }. In other words, V must be identical across migration path graphs sharing the same base structure, but P will differ between those paths that are symmetrically distinct. Image nodes' coordinates are linearly interpolated along the displacement vector between v s and v e .