Study On Numerical Comparison Between Quasi-relativistic Configuration Interaction And Multi-configuration Dirac-Fock Methods And The Properties Of Atoms With Long-range And Short-range Potentials In Intense Laser Fields

By using quasi-relativistic configuration interaction (RHF+CI) and Multi-configuration Dirac-Fock(MCDF) methods, We calculate respectively the electronic mean orbital radius, mean orbital binding energies, total binding energy, excitation energies, fine structure of light and heavy atoms(ions), transition energies for the 2p53s 1,3P1 - 2p6 1S0 of the Ne-like isoelectronic sequence, and make numerical comparison between the two methods. Our results show that the accuracy of the both methods are equivalent for the outer electrons of the atom, but for the heavy atoms transition energies obtained by the MCDF method are better than ones of RHF+CI method. On the other hand, We confirm the ground configuration and the ground state of Lawrencium which dose not claritied by usingRHF+CI method. It is shown that the ground configuration of Lawrencium is 5f 147s27p ,andthe ground state is 2P1/2.Then We also investigate the high harmonic generation and ionization of the long-range and short-range potential atoms by using numerical solution of the time-dependent Schrodinger equation for a one-dimensional atom in intense laser fields. It is found that the intensities of high harmonic generation for both cases are similar, but the short-range potential atom does not radiate the low-order harmonic spectra, and the ionization probabilities of the long-range and short-range potential atoms as a function of the laser intensity are obviously different. Our results show that the excited states of the atom play an important role in the low-order harmonic spectra and ionization probabilities.