Energy, oscillator strength and hyperfine structure of the low-lying excited states for Be-like system

The Rayleigh-Ritz variational method is carried out with a multiconfiguration-interaction wave function and restricted variational method to obtain the relativistic energies of the 1s²2s2p ³P ⁰, 1s²2s2p²³P⁰, and 1s²2p²³P states for the beryllium-like isoelectronic sequence (Z = 4-10), including the mass polarization and relativistic corrections. The oscillator strengths and transition rates are also calculated. The results are compared with other theoretical and experimental data in the literature. The hyperfine structure of the low-lying excited states for this system is also explored.