Mysterious comment about external molecule building with point group symmetry

[hrgrimsl]

There is a comment in molecule_adapters by Nick about loading the two-electron integrals from a JSON file:

    for p, q, r, s, h_pqrs in external_data['tei']['data']:
        qforte_sq_hamiltonian.add(h_pqrs/4.0, [p,q], [s,r]) # only works in C1 symmetry

It is not clear why it should only work in C1, and all testing suggests it works fine with other point groups. I have ignored it in other code I've written, but am making a note of it here.