Jonathan Vandermause

In the OTF class, force_only is set to False by default, but the implemented DFT interfaces return forces only. Should make it clear to users that the ASE OTF class...

OTF and GPFA have duplicated code

1

We can create a parent class, or perhaps better, just write independent functions that both classes call.

timing, scripts, parallel_tests, and nnp directories can be deleted

#TODO: Add a check in compute_varmap_coefficients that the size of the covariance matrix matches the number of sparse environments