Calculations Of 1s～2ns-1s～25p(2≤n≤4) Transition Energies And Oscillator Strengths For Lithium-Like Systems From Z=11 To 20

The transition energies 1s2ns 2S1/2 -1s25p 2P1/2,3/2 (2≤n≤4) of lithium-like systems with nuclear charge from Z=11 to 20 are calculated by using a full-core plus correlation (FCPC) method. The non-relativistic energies and wave functions are calculated by Rayleigh-Ritz(s variation method. Relativistic and mass-polarization effects on the energies are included as the first-order perturbation corrections. The quantum-electrodynamics contributions to the transition energy are also evaluated by using effective nuclear charge. The results are in excellent agreement with experimental data in the literature. The dipole oscillator strengths 1s2ns-1s25p (2≤n≤4) of these ions are calculated by using our FCPC wave functions.