Predictions for Cosmological Infrared Surveys from Space with the Multiband Imaging Photometer for SIRTF

Relativistic quantum defect orbital (RQDO) formalism is applied to the study of forbidden transitions in the astrophysically important ion Mg II. The RQDO calculations have been performed in the LSJ coupling scheme on E2 inter- and intraconfiguration transitions. Line strengths, oscillator strengths, and Einstein coefficients are reported and compared with the data found in the literature. A good agreement with the comparative data as well as the expected systematic behavior of the RQDO line strengths along the spectral series confirms earlier conclusions about the quality of the RQDO wave functions. The E2 spectrum of Mg II is graphically shown.