The effect of residual interactions on the Coulomb energy separation between analogue states is examined in the same spirit and accuracy with which residual interactions are handled in nuclear physics. A closed-form expression allows for simple calculational procedures. The dependence on the form of the residual interaction can then be easily explored. A specific calculation is made for the Ca isotopes; the effect of configuration mixing is studied.

• Received 24 July 1969

DOI:https://doi.org/10.1103/PhysRev.188.1747