Relativistic corrections to spin-forbidden electric-dipole transitions

This is the authors' abstract. We don't add key points for this paper.

Theoretical results for spin-forbidden electric-dipole transitions have recently been questioned on the grounds that relativistic corrections to the transition operator were not included. It is shown here that these corrections are automatically included when the transition operator is expressed in the dipole length form. The above criticism of previous dipole-length calculations is therefore unfounded. The 1s2p 3 P 1 -1s 2 1 S 0 and 1s2p 3 P 1 -1s2s 1 S 0 transitions of helium are discussed as specific numerical examples.