Configuration1s22s3pin the sequence Ne VII—Fe XXIII: Level energies and lifetimes

Abstract

Energies were computed for the $2s3p$ levels in the Be isoelectronic sequence from $Z=10\mathrm{} \mathrm{to} 26$. Multiconfiguration wave functions of form ($2s3p$,$2p3s$,$2p3d$)were obtained from the program MCHF77. The Pauli relativistic corrections were calculated and the 2×2 spin-orbit-interaction matrix was diagonalized to obtain the ${}_{}{}^1{}_{}{}^{}P_1^{}{}_{}{}^{}-{}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}$ interval and mixing coefficient. Results agree with observations and with other self-consistent-field calculations at $Z=10, 23, \mathrm{and} 26$. The avoided crossing of the two $J=1\mathrm{}$ levels is found to occur at $Z=21\mathrm{}$. Finally, the radiative-decay probabilities of the mixed $J=1\mathrm{}$ levels were calculated; results are compared with other calculations and checked against a recent experiment in Ne VII.