Abstract
Transition probabilities are evaluated for the 2s2p 3P1 to 2s2 1S0 transition in beryllium-like ions for Z=4-10 and Z=14, using configuration-interaction wavefunctions. The convergence of the results with respect to the basic set of orbitals is considered. The question of at what stage the Breit interaction should be included in the Hamiltonian is discussed.