Session J15 - Poster Session II.
POSTER session, Sunday morning, April 20
Congressional Hall, Renaissance
Results from large-scale multiconfiguration Dirac-Fock and configuration interaction calculations including the Breit interaction are presented for intercombination and forbidden transitions in C~III and in the Mg iso-electronic sequence. In the calculations the orbital sets of the initial and final state wave functions were not restricted to be the same, but were optimized independently to ensure an accurate description of both states. The evaluation of the transition matrix elements was done using a technique where the two orbital sets are transformed so as to become biorthonormal, in which case standard Racah algebra can be used. The predicted transition probability for the 2s^2~^1S_0 - 2s2p~^3P_1 transition in C~III is A=102.9\pm 1.3 s^-1 and is in excellent agreement with with a recent storage ring measurement. For the 3s^2~^1S_0 - 3s3p~^3P_1 transition in Al~II and Si~III the theoretical values of the transition probabilities are lower that experimental values from ion trap experiments.