The code here is incredibly messy. It's pared down from a completely different project, and I did this while anxious to get multislice simulations working with my ANN work. The multislice code is EJ Kirkland's implementation, with some changes by me. It's still contains much that is not actually used here. The code is probably very difficult to follow at the moment, and I implore you not to even look at it.
I will eventually tidy it up (unless I get this working at a reasonable speed in python first), and add more functionality including, probably, a GUI. In the mean time, I will at the very least get instructions up soon so that it's usable for its currently intended purpose.