The calculation of the line strengths for magnetic dipole transitions between the 2s(2), 2s2p and 2p(2) states in Be-like ions

In this paper we derive a simple approximation to calculate the line streng ths for magnetic dipole transitions between the 2s(2), 2s2p and 2p(2) state s of Be-like ions. This approximation only requires a knowledge of the coef ficients in the expansion of the configuration interaction wave functions o f the states involved in the transition and Wigner 6-j symbols. Results are obtained for a range of Be-like ions from B II to K XXXIII. There is very good agreement between our approximate results and the results of the full calculations of Kingston and Hibbert (J. Phys. B 33, 81, 2000). The only ma jor differences between the two calculations occur for B II.