Theoretical Research On The Energy Structure And Oscillator Strength Of Excited States For Cr²¹⁺ Ion

The developments of atomic and molecular physics are introduced briefly.the discipline status, the present main research contents and the development directions are commented firstly. After the summarization of the methods in the theory of atomic structure, the principle and the achievement of Full-core plus correlation (FCPC) are narrated in detail.In this paper, FCPC method is extended to calculated the energy structures of 1s²nl (l = p,d, f; n≤9) states for Cr²¹⁺ ion. The non-relativistic energies and wave functions are calculated by using Rayleigh-Ritz's variation method. Relativistic and mass-polarization effects on the energies are included as the first-order perturbation .The quantum-electrodynamics contribution are evaluate by using effective nuclear charges .For obtaining the high-precision theoretical results, the correction of core and the higher l contributions to the energy are also calculated. The fine structure is calculated by using the spin-orbit and the spin-other-orbit interactionoperators.The quantum defects of ls²nl(l= p,d,f; n≤9) three Rydberg series for Cr²¹⁺ion are determined by the single-channel quantum defect theory. The energies of any highly excite states with n≥10 also can be reliably predicted by using the quantum defects which are function of energy.The dipole oscillator strengths for the 1s² np-1s² nd and 1s² nd-1s² nf(n≤9) transitions of Cr²¹⁺ion are also calculated with FCPC wave functions obtained above. Combining the single channel quantum defect theory with the discrete oscillator strengths, the oscillator strengths for transitions and the oscillator strength densities corresponding to the bound-free transitions from a certain initial state to all final states of the Rydberg series are also obtained, and realize the theoretical research on the property of the whole energy region for Cr²¹⁺ dipole transitions.