Excited-state energies and fine structure of highly charged lithiumlike ions

Abstract

The full-core-plus-correlation method (FCPC) is extended to calculate the energies and fine structures of 1${s}^{2}nd$ and 1${s}^{2}nf$ ($n\ensuremath{\le}5$) states for the lithiumlike systems with high nuclear charge from $Z$ $=$ 41 to 50. In calculating energy, the higher-order relativistic contribution is estimated under a hydrogenic approximation. The nonrelativistic energies and wave functions are calculated by the Rayleigh-Ritz method. The mass polarization and the relativistic corrections including the kinetic energy correction, the Darwin term, the electron-electron contact term, and the orbit-orbit interaction are calculated perturbatively as the first-order correction. The quantum-electrodynamics contributions to the energy and to the fine-structure splitting are estimated by using the effective nuclear charge formula. The excited energies, the fine structures, and other relevant term energies are given and compared with the data available in the literature.