| The nature of highly ionized and highly excited systems for highly chargedlithiumlike ions plays an important role in laser physics, X-ray astrophysics, plasmaphysics, and many other areas of physics. So it becomes a research area with highlyinterest of atomic physics.In this thesis, the history and current status of the atomic and molecular physicsfor highly charged atoms are briefly reviewed. The significance of research for highionized atomic (HIA) system, especially for three electronic system with1s2-core issummarized. By comparing the calculation methods for atomic structure, the mainidea and advantages of the full core plus correletion (FCPC) method are reported withits some important results.We have extended FCPC method in this study for calculation of energies, finestructures and oscillator strengths for lithium-like isoelectronic sequence systems1s2nl (l=s,p,d,f；n≤5) with high nuclear charges from Z=41to50. The nonrelativisticenergies and wave functions are determined by using Rayleigh-Ritz method. Inadditional, the relativity corrections for the energy calculation, including the kineticenergy correction, the Darwin term, the electron-electron contact term, the orbit-orbitinteraction, and mass-polarization, are calculated perturbatively as a first-ordercorrection. In order to get more precise theoretical values, the quantum-electrodynamics contribution to the energies and to the fine-structure splittings are estimated by using the effective nuclear charge formula. Core correction and high lcontribution are also estimated. In addition, the higher-order relativistic contributionis evaluated under a hydrogenic approximation. The fine structure splittings areobtained by calculating the expectations of spin-orbit and spin-other orbitalinteractions with the wave functions obtained based the methods mentioned above.The excited energies, the fine structures, and other relevant term-energies are obtained.By compared with the previous works, the results from the present study are inagreement with these data available in the literatures. We compared the nonrelativisticoscillator strengths with the relativistic theoretical results in detail and discussed theinfluence of relativistic effects on the oscillator strengths for different Z values. Theresults in this study are in agreement with the theoretical data available in theliterature.According to the obtained translations and wave functions, the three kinds ofdipole transition oscillator strengths are calculated and their values are almostconsistent. This indicates that the obtained transition energies and wave functionsfrom the FCPC methods are accurate and reliable from near nuclear area to the areafar away from the nuclear. In addition, the relativistic oscillator strengths are alsocalculated, and we compared the non-relativistic oscillator strength with relativistictheoretical results in detail, and discussed the influence of relativistic effects to theoscillator strengths for lithium-like isoelectronic sequence systems with different Zvalues.So far, the experimental data on the energy structures and transition property forthe lithium-like systems with high nuclear charge is rare. Therefore the present studyfrom our theoretical calculation gives some reliable predictions. We sincerely hopethat the present theoretical results can play a role to contribute in the related fields ofatomic physics and other areas. |
