Migrate Gaussian basis evaluation to gau2grid #2554
Description
Gau2Grid is a generated C library for efficient calculation of Gaussian basis sets on grids (e.g., molecular orbitals, electron density, spin density):
https://gau2grid.readthedocs.io/en/latest/
It's almost certainly more efficient than our current implementation (it's optimized and vectorized) and supports higher angular momenta than we do.
It would be great to port gaussiansettools to use gau2grid.