Nontransferable Correlation Effects and Multiplet Oscillator Strengths for Electric Dipole Transitions in Atoms with Results on C ii, N i, N ii, N III, O ii, O III, O iv, F ii, and NE II

Wave functions which include selected, state-dependent correlation effects are used to evaluate multiplet oscillator strengths for a number of 1s22s22p~ -> 1s22s2p~ electric dipole transitions in the first-row atoms and ions. It has long been known that those transitions cannot be accurately calculated within the Restricted llartree-Fock approximation. Our results show that the usual improvement on this scheme, the mixing of those few configurations nearly degenerate with the Restricted Hartree-Fock (RHF) configuration, is by itself incapable of bringing the oscillator strengths into agreement with ex- perimental values. Additional correlation effects which show up in the open-shell many-electron theory of atomic structure (MET) developed recently by Sinano~1u and co-workers need also be considered. Calculations including all these highly state-dependent correlation effects yield very good agreement with available experimental values. These calculated oscillator strengths, together with many more for which experimental results are not available, are tabulated