Relativistic many-body calculations of transition amplitudes for berylliumlike ions - art. no. 042507

Transition amplitudes for allowed transitions in Be-like ions are determine d to second order within the framework of relativistic many-body perturbati on theory. The calculations start with a V(N-2) Dirac-Fock potential and in clude correlation corrections systematically. Multiconfiguration reference states are employed to account for the valence-valence correlations within the valence shell and perturbation theory is applied to systematically impr ove upon the wave functions. The transition amplitudes obtained in differen t gauges are in close agreement. The theoretical transition amplitudes agre e well with experiment for all ions except for the neutral Be atom.