ENERGIES, FINE-STRUCTURES AND OSCILLATOR-STRENGTHS OF 1S(2)2P(2) S-1,D-1 AND P-3(2,1,0) STATES OF BE-LIKE IONS

The energies and wave functions of the 1s(2)2p(2 1)S, P-3 and D-1 stat es are calculated with a full-core plus correlation method (FCPC) for ions from B II to Ne VII, Mg IX and Si XI. A restricted variational me thod is used to extrapolate a better nonrelativistic energy. The relat ivistic correction and fine structures are calculated with first-order perturbation theory. Higher order effects are estimated. The oscillat or strengths for 1s(2)2snp (n = 2, 3) P-1(o)-1s(2)2p(2 1)S, D-1 and fo r 1s(2)2snp (n = 2, 3) P-3(o)-1s(2)2p(2 3)P are calculated. The result s are compared with available theoretical and experimental data in the literature. The excitation energies predicted in this work are slight ly higher than the precision experiment. For example, for D-1, it is h igher by 8.5 cm(-1) for Z = 4 and the discrepancy increases to 149 cm( -1) for Z = 14. The dipole-length, -velocity and -acceleration oscilla tor strengths calculated in this work agree well with each other. Howe ver, some discrepancies still exist between the predicted oscillator s trengths and experiment.