I have a 1D discrete, finite system that lacks translational invariance. It appears to have edge states, in much the same way as an SSH model has edge states. In the SSH model we can study the infinite version of the finite chain to calculate a topological index, the Zak phase. I am trying to think if I can define (or there already exists) some kind of topological index that captures the presence of these edge states. However my system lacks translational invariance. Any suggestions on how to approach this? I have found the Bott index, but it appears to only be defined for 2D systems.