Relaxation and polarization effects in photodetachment of the negative iodide ion

Photodetachment cross sections have been calculated for the 5p, 4d, and 4p subshells of the negative iodide ion, I{sup -}, in the relativistic random-phase approximation (RRPA) and modifications of the RRPA that allow for the inclusion of relaxation and core-polarization effects. Total and partial photodetachment cross sections are compared with experimental measurements to gauge the effectiveness of the various approximations. Branching ratios and photoelectron angular-distribution asymmetry parameters are also presented. Core-polarization effects are found to partially cancel relaxation effects.