Energies and hyperfine structures of the [1s.sup.2]2s2p [sup.3][P.sup.o] state of Be-like ions with Z = 11-18

Nonrelativistic energies and wave functions of the [1s.sup.2]2s2p [sup.3][P.sup.o] states of Be isoelectronic sequence (Z = 11-18) are calculated using the full core plus correlation method (FCPC). To obtain the accurate energy level, the relativistic corrections and mass polarization effect are included by using the first-order perturbation theory. The calculated excitation energies (relative to the [1s.sup.2][2s.sup.2] ground state) are compared with the experiment. Most of the calculated [sup.3][P.sup.o.sub.j] energies agree with the experiment to within a few inverse centimetres. The calculated hyperfine coupling constants are in good agreement with the latest theoretical data in the literature. Our results may provide valuable reference data for spectral analysis and identification in the future. Key words: Be-like ions, excitation energies, hyperfine structure, nonrelativistic energies, relativistic corrections. Resume : Nous utilisons le creur en entier plus la methode de correlations (FCPC) pour calculer les energies non relativistes et les fonctions d'onde des etats [1s.sup.2]2s2p [sup.3][P.sup.o] de la sequence (Z = 11-18) isoelectronique du Be. Afin d'obtenir des valeurs precises pour les niveaux d'energie, nous incluons les corrections relativistes et les effets de polarisation de masse au premier ordre de la theorie des perturbations. Les valeurs d'energie d'excitation calculees (relative au fondamental [1s.sup.2][2s.sup.2]) sont comparees aux valeurs experimentales et la plupart des energies [sup.3][P.sup.o.sub.j] calculees ne different des valeurs experimentales que de quelques [cm.sup.-1]. Les constantes de couplage hyperfin calculees sont en bon accord avec les plus recentes donnees theoriques dans la litterature. Nos resultats peuvent servir de reference interessante pour des analyses spectrales et des identifications dans le futur. [Traduit par la Redaction] Mots-cles: ions de type Be, energies d'excitation, structure hyperfine, energies non relativists, corrections relativists.
1. Introduction The low-lying excited states [1s.sup.2]2s2p [sup.3][P.sup.o] of Be-like ions, where two electrons are closed to the [1s.sup.2] core, is an ideal system for investigating hyperfine effects and testing [...]