gpaw-raman-script
Implements https://www.nature.com/articles/s41467-020-16529-6
(Note: since starting development on this, gpaw now also has its own implementation of this method currently in development, but it doesn't allow symmetry-reduced displacements)
Guided example
https://gist.github.com/ExpHP/49c1cdd3d34a24aa7414ac9d724e13a3