Theoretical Research On The Energy Structure And Oscillator Strength Of Sc～(18+)

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 occasion that highly excited and highly charged ions have been the important research area is expounded. Then the main methods and the results obtained on processing the lithium-like atomic systems are introduced. The principle and the achievement of Full-core plus correlation (FCPC) are narrated in detail, and the method is extended to lithium-like systems with the higher nuclear charge. The ionization potentials and excitation energies of 1s2ns, 1s2np, and 1s2nd (n ≤9)states for Sc18+ are calculated. The non-relativistic energies and wave functions are calculated by using Rayleigh-Ritz′s variation method. Relativistic and mass-polarization effects are included as the first-order perturbation. The contributions of quantum -electrodynamics are evaluated by using effective nuclear charge. For obtaining the high-precision theoretical results, the correction of core and the higher l contributions to the energy are also calculated. The fine structures are determined by computing the expectation values of the spin-orbit and spin-other orbit interaction operators. Based on the energies of the excited states for lithium-like systems from the FCPC method, the quantum defects of three Rydberg series for Sc18+ are determined with the single channel quantum defect theory. With the quantum defects as input, the energies of excited states from the FCPC method are calculated again by semi-empirical method. Finally, the dipole oscillator strengths of the three forms are obtained with the wave function and transition energies from the FCPC method. Combined with the single channel quantum defect theory, the oscillator strengths for transitions and the oscillator strength densities corresponding to the bound-free transitions from a certain initial state to all the final states of the Rydberg series are also obtained, and realize the theoretical research on the property of the whole energy region for Sc18+ dipole transitions.