A simplified calculation of the radiative recoil correction to hydrogenic energy levels in ${\mathit{m}}^2$/M[α(Zα${)}^5$/${\mathit{n}}^3$] order is presented. The method is based on evaluation of the proton kinetic energy term in the electron state. The result obtained is in disagreement with a previous calculation of Bhatt and Grotch [Ann. Phys. (N.Y.) 178, 1 (1987)]. We also analyze the nuclear self-energy contribution and the corresponding definition of the nuclear mean square charge radius.

• Received 24 February 1995

DOI:https://doi.org/10.1103/PhysRevA.52.1079