I recently used this piece of code to calculate the unrelaxed dipole moment (with either MP2 or CCSD) by finite field method. However, the result seems fairly off in magnitude. Is there anything wrong I did?
pert = 1.8897261250e-5
scf_e, scf_wfn = energy(‘scf’, return_wfn=True)
mints = psi4.core.MintsHelper(scf_wfn)
dipole = mints.ao_dipole()
dipole.scale(pert) # dipole_x perturbation
Perturb_matrix = scf_wfn.Fa()
dpx = psi4.get_variable(‘MP2 DIPOLE X’)