Overlap matrix S(B) of perturbation-dependent atomic orbitals

[cyberturist]

Dear devs,

thank you for this awesome module!
Is it possible to print the overlap matrix of gauge-invariant atomic orbitals S(B) in the calculation of NMR or magnetizabilities?

[sunqm]

No, the field-included integrals are not available. If you just need to compute the first order term, mol.intor('int1e_igovlp') can compute the summation of two overlap integrals $<e^{i R_p\times r \cdot B} \chi_p|\chi_q> + <\chi_p|e^{i R_q\times r \cdot B} \chi_q>$ .