In the above expansion of Ĥdse we have specifically indicated that the product of electronic dipole operators contains 2electron contributions when i = j, and 1-electron quadrupole contributions when i = j. The quadrupole contributions arise from the fact that μξ (x i ) μξ (x i ) = -Qξξ (x i ). Furthermore, a one-electron term arises that contains the electronic dipole operator scaled by λ • µ nucλ • µ , where again µ will be iteratively updated during the CQED-RHF procedure.