Corrections to hyperfine splitting and Lamb shift induced by diagrams with second-order radiative insertions in the electron line

Contributions to HFS and to the Lamb shift intervals of order /spl alpha//sup 2/(Z/spl alpha/)/sup 5/ induced by a gauge invariant set of 19 topologically different graphs with two radiative photons inserted in the electron line are considered. Corrections both to HFS and Lamb shift induced by nine of these 19 diagrams have been calculated in the Fried-Yennie gauge.