I am excited about the NumPy psi4 project

https://github.com/psi4/psi4numpy

Just wondering about the tensor contractions. It seems that it was evaluated by einsum in NumPy, e.g., https://github.com/psi4/psi4numpy/blob/master/Coupled-Cluster/Spin_Orbitals/CCSD/CCSD_T.py. One may do so by a series of BLAS in a lower-level language, e.g., C++/Fortran.

Is there any comparison for the efficiency of quantum chemical calculations? I saw some benchmark on https://stackoverflow.com/questions/7596612/benchmarking-python-vs-c-using-blas-and-numpy

the results seem to vary a lot.