Copy of Numpy-based basis functions utilities from e3x.

Useful external APIs:

• BasisLib.so3.generate_clebsch_gordan_lookup_table: Current .npz cache supports upto lmax=30
• BasisLib.so3.generate_spherical_harmonics_lookup_table: Current .npz cache supports upto lmax=15

Refer to BasisLib.so3.spherical_harmonics and BasisLib.so3.clesch_gordan for their usage.

python -m BasisLib.so3.clebsch_gordan_lut --path $HOME/BasisLib/BasisLib/so3_clebsch_gordan_lut.npz --max_degree 50 --num_processes 47