Discrete Shannon entropy is applied to describe the information in a multiconfiguration Dirac Fock wavefunction. The dependence of Shannon entropy is shown as enlarging the configuration space and it can reach saturat...Discrete Shannon entropy is applied to describe the information in a multiconfiguration Dirac Fock wavefunction. The dependence of Shannon entropy is shown as enlarging the configuration space and it can reach saturation when there are enough configuration state wavefunctions to obtain the convergent energy levels; that is, the calculation procedure in multiconfiguration Dirae Fock method is an entropy saturation process. At the same accuracy level, the basis sets for the smallest entropy are best able to describe the energy state. Additionally, a connection between the sudden change of Shannon information entropies and energy level crossings along with isoelectronic sequence can be set up, which is helpful to find the energy level crossings of interest in interpreting and foreseeing the inversion scheme of energy levels for an x-ray laser.展开更多
Energy levels, wavelengths, transition rates, oscillator strengths, and lifetimes between the 2s22p23P1,2s22p23P2,and 2s2p35S2 levels of ions in the carbon-like （C-like） isoelectronic sequence （nuclear charges Z=7...Energy levels, wavelengths, transition rates, oscillator strengths, and lifetimes between the 2s22p23P1,2s22p23P2,and 2s2p35S2 levels of ions in the carbon-like （C-like） isoelectronic sequence （nuclear charges Z=7-92） are calculated in the valence and core-valence limits using the multiconfiguration Dirac–Fock method. The Breit interaction, quantum electrodynamics （QED）, and finite nuclear mass effects are taken into account in subsequent relativistic configuration-interaction calculations. The calculated energies and transition rates are compared with the critically evaluated experimental values and other recent calculated results. Our calculated data are in good agreement with these data.展开更多
This paper calculates the transition wavelengths and probabilities of the two-electron and one-photon （TEOP） transition from the （3s1/2^-14dj）J=1,2 to （3P3/2^-14s1/2）J=1 and the （3P1/2^-14s1/2）J=1 to （3dj^-1...This paper calculates the transition wavelengths and probabilities of the two-electron and one-photon （TEOP） transition from the （3s1/2^-14dj）J=1,2 to （3P3/2^-14s1/2）J=1 and the （3P1/2^-14s1/2）J=1 to （3dj^-14dj＇）J=1,2 for highly charged Ni-like ions with atomic number Z in the range 47 〈 Z 〈 92. In the calculations, the multi-configuration Dirac-Fock method and corresponding program packages GRASP92 and REOS99 were used, and the relativistic effects, correlation effects and relaxation effects were considered systematically. It is found that the TEOP transitions are very sensitive to the correlation of electrons, and the probabilities will be enhanced sharply in some special Z regions along the isoelectronic sequence. The present TEOP transition wavelengths are compared with the available data from some previous publications, good agreement is obtained.展开更多
Energy levels, radiative rates, and lifetimes are calculated for all levels of 3s23p, 3s23d, 3s3p2, 3s3d2, 3s3p3d, 3p23d, 3s3d2, 3p3d2, 3p3, and 3d3 configurations of Al-like tungsten ion （W XLVII）. Multiconfigurati...Energy levels, radiative rates, and lifetimes are calculated for all levels of 3s23p, 3s23d, 3s3p2, 3s3d2, 3s3p3d, 3p23d, 3s3d2, 3p3d2, 3p3, and 3d3 configurations of Al-like tungsten ion （W XLVII）. Multiconfigurational Dirac-Fock （MCDF） method is adopted for calculating energy levels and radiative rates. Oscillator strengths, radiative rates, and line strengths are reported for some E1 transitions from the ground level. Comparisons are made with the available data in the literature and good agreement has been found which confirms the reliability of our results.展开更多
In this paper, we explored the characteristics of the interference effects between perturbative states in hyperfine induced 2s2p ^3p0,^3p2→ 2s^21S0 transitions of Be-like ions. It was found that the interference effe...In this paper, we explored the characteristics of the interference effects between perturbative states in hyperfine induced 2s2p ^3p0,^3p2→ 2s^21S0 transitions of Be-like ions. It was found that the interference effects non-monotonically change with increasing atomic number Z in these two transitions. The strongest interference effect is near Z = 9 for 2s2p^3P0→2s^21S0 transition and near Z = 7 for the other.展开更多
This paper calculates the electron impact excitation rate coefficients from the ground term 2s^22p^2 3p to the excited terms of the 2s^22p^2, 2s^2p^3, 2s^22p3s, 2s^22p3p, and 2s^22p3d configurations of N II. In the ca...This paper calculates the electron impact excitation rate coefficients from the ground term 2s^22p^2 3p to the excited terms of the 2s^22p^2, 2s^2p^3, 2s^22p3s, 2s^22p3p, and 2s^22p3d configurations of N II. In the calculations, multiconfiguration Dirac-Fork wave functions have been applied to describe the target-ion states and relativistic distorted-wave calculation has been performed to generate fine-structure collision strengths. The collision strengths are then averaged over a Maxwellian distribution of electron velocities in order to generate the effective collision strengths. The calculated rate coefficients are compared with available experimental and theoretical data, and some good agreements are found for the outer shell electron excitations. But for the inner shell electron excitations there are still some differences between the present calculations and available experiments.展开更多
The photo-excitation and Auger decay processes of inner-shell double vacancy states 1s2s2p^6（1,3^S）3s3p of neutral neon atoms have been studied theoretically. Multi-configuration Dirac-Fock （MCDF） calculations hav...The photo-excitation and Auger decay processes of inner-shell double vacancy states 1s2s2p^6（1,3^S）3s3p of neutral neon atoms have been studied theoretically. Multi-configuration Dirac-Fock （MCDF） calculations have been carried out, with electron correlation effects taken into consideration. The relaxation of core and excited orbitals and configuration interaction are found to be crucial to creating the double vacancy states by single photo-absorption. The predominant decay paths for the double vacancy states turn out to be of the LLM Auger decay to 1s 2s^22p^53s（3p）, KLL Auger decay to 1s^22s2p^43s3p, and KLM Auger decay to 1s^22p^63s（3p）. They lead to further Auger decay, creating the neon ions of multiple charge states. For both double and single vacancy states the spectator type of Auger process is dominated in all the Auger decay processes. Theoretical Anger electron spectra are presented for further investigations, experimental and theoretical.展开更多
By using soft X-ray spectroscopy, we investigate the inner-shell excitation and relaxation processes in atomic and ionic neon targets. Resonant X-ray emission spectroscopy was applied to neutral neon atom in the regio...By using soft X-ray spectroscopy, we investigate the inner-shell excitation and relaxation processes in atomic and ionic neon targets. Resonant X-ray emission spectroscopy was applied to neutral neon atom in the regions of the [1s]np （n = 3, 4,…, ε） excited states and [1s2p]3pmp （m = 3,4） doubly excited states to obtain the spectroscopic information on the [2p]np and [2p^2]3prnp final electronic states, where square brackets indicate hole states. The energy levels of the [2p^2]3prnp （m = 3,4） electronic states were spectroscopically measured for the first time. As for the ionic neon target, on the other hand, the photoion yield spectroscopy was adopted to survey the 1s→ np （n = 2, 3） resonant excitation and subsequent Auger decay processes for Ne^＋ target-ions. The observed Ne^2＋ photoion yield spectrum is successflllly explained by the theoretical calculations based on the nmlticonfiguration Dirac-Fock method展开更多
Theoretical calculations of the energy levels and magnetic dipole transition parameters for the 1s^(2)2s^(2)2p^(3) and 1s^(2)2p^(5) configurations of nitrogen isoelectronic sequence with Z=21-30 are performed using mu...Theoretical calculations of the energy levels and magnetic dipole transition parameters for the 1s^(2)2s^(2)2p^(3) and 1s^(2)2p^(5) configurations of nitrogen isoelectronic sequence with Z=21-30 are performed using multi-congfiguration Dirac-Fock(MCDF)method.Based on the relativistic computational code GRASP2k compiled within the framework of MCDF method,the electron correlations,Breit interaction and QED effects are well treated in detail.The energy levels,line strengths and transition rates of magnetic dipole transition are obtained and compared with the experimental data avail-able.For most cases,good agreements are achieved and the relative differences of them are less than 0.114%,8.43% and 9.80%,respectively.The scaling laws of the fine structure splitting and transition rate are obtained on the isoelec-tronic sequence and the corresponding physical mechanisms are discussed.The data sets for tables are openly available at https://www.doi.org/10.57760/sciencedb.j00113.00022.展开更多
Highly charged nickel ions have been suggested as candidates for the ultra-precise optical clock, meanwhile the relevant experiment has been carried out. In the framework of the multiconfiguration Dirac–Hartree–Fock...Highly charged nickel ions have been suggested as candidates for the ultra-precise optical clock, meanwhile the relevant experiment has been carried out. In the framework of the multiconfiguration Dirac–Hartree–Fock(MCDHF)method, we calculated the hyperfine interaction constants, the Landég-factors, and the electric quadrupole moments for the low-lying states in the 61Ni11+,61Ni12+,61Ni14+, and61Ni15+ ions. These states are clock states of the selected clock transitions in highly charged nickel ions(see Fig. 1). Based on discussing the effects of the electron correlations, the Breit interaction, and quantum electrodynamics(QED) effect on these physical quantities, reasonable uncertainties were obtained for our calculated results. In addition, the electric quadrupole frequency shifts and the Zeeman frequency shifts of the clock transitions concerned were analyzed.展开更多
铜原子能级结构的理论计算具有非常大的挑战性。本文基于多组态Dirac-Hartree-Fock(MCDHF)方法和相对论组态相互作用(RCI)方法,通过三个大规模的关联模型计算了单激发态3d^104p2P1/2、双激发态3d94s(3D)5s4D3/2,1/2,3d94s(3D)5s2D3/2,3d...铜原子能级结构的理论计算具有非常大的挑战性。本文基于多组态Dirac-Hartree-Fock(MCDHF)方法和相对论组态相互作用(RCI)方法,通过三个大规模的关联模型计算了单激发态3d^104p2P1/2、双激发态3d94s(3D)5s4D3/2,1/2,3d94s(3D)5s2D3/2,3d94s(1D)5s2D3/2以及离子态3d101S0能级和波函数。结果表明,铜原子能级结构对有限组态空间的选择极其敏感,双激发态3d94s(3D)5s4D3/2,1/2,3d94s(3D)5s2D3/2,3d94s(1D)5s2D3/2和离子态3d101S0与单激发态之间的能量差相对于已有实验结果均存在大约-0.4 e V的偏差,而计算得到的共振电子能量与实验结果符合得较好。此外,根据辐射跃迁矩阵元和非辐射跃迁矩阵元计算了双激发态的Fano参数q,并基于Fano理论得到了铜单激发态3d^104p2P1/2的总光电离截面,该理论考虑了直接光电离与光激发自电离之间的干涉效应,即共振3d94s(3D)5s4D3/2,1/2、3d94s(3D)5s2D3/2和3d94s(1D)5s2D3/2具有明显的非对称的Fano轮廓,表明光电离过程与光激发自电离过程之间的干涉对双激发态共振附近的光电离截面轮廓有着极其重要的影响。展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 11204243the Foundation of Northwest Normal University under Grant No NWNU-LKQN-10-7
文摘Discrete Shannon entropy is applied to describe the information in a multiconfiguration Dirac Fock wavefunction. The dependence of Shannon entropy is shown as enlarging the configuration space and it can reach saturation when there are enough configuration state wavefunctions to obtain the convergent energy levels; that is, the calculation procedure in multiconfiguration Dirae Fock method is an entropy saturation process. At the same accuracy level, the basis sets for the smallest entropy are best able to describe the energy state. Additionally, a connection between the sudden change of Shannon information entropies and energy level crossings along with isoelectronic sequence can be set up, which is helpful to find the energy level crossings of interest in interpreting and foreseeing the inversion scheme of energy levels for an x-ray laser.
基金the National Natural Science Foundation of China(Grant No.11174213)
文摘Energy levels, wavelengths, transition rates, oscillator strengths, and lifetimes between the 2s22p23P1,2s22p23P2,and 2s2p35S2 levels of ions in the carbon-like （C-like） isoelectronic sequence （nuclear charges Z=7-92） are calculated in the valence and core-valence limits using the multiconfiguration Dirac–Fock method. The Breit interaction, quantum electrodynamics （QED）, and finite nuclear mass effects are taken into account in subsequent relativistic configuration-interaction calculations. The calculated energies and transition rates are compared with the critically evaluated experimental values and other recent calculated results. Our calculated data are in good agreement with these data.
基金supported by the National Natural Science Foundation of China (Grant Nos 10434100 and 10774122)the Foundation of China/Ireland Science and Technology Collaboration Research (Grant No CI-2004-07)+2 种基金the Foundation of the Center of Theoretical Nuclear Physics,National Laboratory of Heavy Ion Accelerator of Lanzhouthe Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No 20070736001)the Foundation of Northwest Normal University of China(Grant Nos NWNU-KJCXGC-03-21 and NWNU-QN-2003-28)
文摘This paper calculates the transition wavelengths and probabilities of the two-electron and one-photon （TEOP） transition from the （3s1/2^-14dj）J=1,2 to （3P3/2^-14s1/2）J=1 and the （3P1/2^-14s1/2）J=1 to （3dj^-14dj＇）J=1,2 for highly charged Ni-like ions with atomic number Z in the range 47 〈 Z 〈 92. In the calculations, the multi-configuration Dirac-Fock method and corresponding program packages GRASP92 and REOS99 were used, and the relativistic effects, correlation effects and relaxation effects were considered systematically. It is found that the TEOP transitions are very sensitive to the correlation of electrons, and the probabilities will be enhanced sharply in some special Z regions along the isoelectronic sequence. The present TEOP transition wavelengths are compared with the available data from some previous publications, good agreement is obtained.
基金D. S. T. (INDIA)U. G. C. (INDIA)the University of Delhi under R & D research programme
文摘Energy levels, radiative rates, and lifetimes are calculated for all levels of 3s23p, 3s23d, 3s3p2, 3s3d2, 3s3p3d, 3p23d, 3s3d2, 3p3d2, 3p3, and 3d3 configurations of Al-like tungsten ion （W XLVII）. Multiconfigurational Dirac-Fock （MCDF） method is adopted for calculating energy levels and radiative rates. Oscillator strengths, radiative rates, and line strengths are reported for some E1 transitions from the ground level. Comparisons are made with the available data in the literature and good agreement has been found which confirms the reliability of our results.
基金supported by National Natural Science Foundation of China (Nos. 10774122, 10876028)the specialized Research Fund for the Doctoral Program of Higher Education of China (No.20070736001)the Foundation of Northwest Normal University of China (NWNU-KJCXGC-03-21)
文摘In this paper, we explored the characteristics of the interference effects between perturbative states in hyperfine induced 2s2p ^3p0,^3p2→ 2s^21S0 transitions of Be-like ions. It was found that the interference effects non-monotonically change with increasing atomic number Z in these two transitions. The strongest interference effect is near Z = 9 for 2s2p^3P0→2s^21S0 transition and near Z = 7 for the other.
基金supported by the National Natural Science Foundation of China (Grant Nos.10774122 and 10876028)the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No.20070736001)the Technology and Innovation Program of Northwest Normal University (Grant No.NWNU-KJCXGC-03-21)
文摘This paper calculates the electron impact excitation rate coefficients from the ground term 2s^22p^2 3p to the excited terms of the 2s^22p^2, 2s^2p^3, 2s^22p3s, 2s^22p3p, and 2s^22p3d configurations of N II. In the calculations, multiconfiguration Dirac-Fork wave functions have been applied to describe the target-ion states and relativistic distorted-wave calculation has been performed to generate fine-structure collision strengths. The collision strengths are then averaged over a Maxwellian distribution of electron velocities in order to generate the effective collision strengths. The calculated rate coefficients are compared with available experimental and theoretical data, and some good agreements are found for the outer shell electron excitations. But for the inner shell electron excitations there are still some differences between the present calculations and available experiments.
基金Project supported by the National Natural Science Foundation of China (Grant Nos 10434100,10774122)the Core-University Program between Japanese Society of Promotion of Science and Chinese Academy of Sciences+1 种基金the Foundation of Center of Theoretical Nuclear Physics of National Laboratory of Heavy Ion Accelerator of Lanzhouthe Foundation of Northwest Normal University (Grant No NWNU-KJCXGC-03-21)
文摘The photo-excitation and Auger decay processes of inner-shell double vacancy states 1s2s2p^6（1,3^S）3s3p of neutral neon atoms have been studied theoretically. Multi-configuration Dirac-Fock （MCDF） calculations have been carried out, with electron correlation effects taken into consideration. The relaxation of core and excited orbitals and configuration interaction are found to be crucial to creating the double vacancy states by single photo-absorption. The predominant decay paths for the double vacancy states turn out to be of the LLM Auger decay to 1s 2s^22p^53s（3p）, KLL Auger decay to 1s^22s2p^43s3p, and KLM Auger decay to 1s^22p^63s（3p）. They lead to further Auger decay, creating the neon ions of multiple charge states. For both double and single vacancy states the spectator type of Auger process is dominated in all the Auger decay processes. Theoretical Anger electron spectra are presented for further investigations, experimental and theoretical.
文摘By using soft X-ray spectroscopy, we investigate the inner-shell excitation and relaxation processes in atomic and ionic neon targets. Resonant X-ray emission spectroscopy was applied to neutral neon atom in the regions of the [1s]np （n = 3, 4,…, ε） excited states and [1s2p]3pmp （m = 3,4） doubly excited states to obtain the spectroscopic information on the [2p]np and [2p^2]3prnp final electronic states, where square brackets indicate hole states. The energy levels of the [2p^2]3prnp （m = 3,4） electronic states were spectroscopically measured for the first time. As for the ionic neon target, on the other hand, the photoion yield spectroscopy was adopted to survey the 1s→ np （n = 2, 3） resonant excitation and subsequent Auger decay processes for Ne^＋ target-ions. The observed Ne^2＋ photoion yield spectrum is successflllly explained by the theoretical calculations based on the nmlticonfiguration Dirac-Fock method
基金Project supported by the National Natural Science Foundation of China(Grant No.12175096)。
文摘Theoretical calculations of the energy levels and magnetic dipole transition parameters for the 1s^(2)2s^(2)2p^(3) and 1s^(2)2p^(5) configurations of nitrogen isoelectronic sequence with Z=21-30 are performed using multi-congfiguration Dirac-Fock(MCDF)method.Based on the relativistic computational code GRASP2k compiled within the framework of MCDF method,the electron correlations,Breit interaction and QED effects are well treated in detail.The energy levels,line strengths and transition rates of magnetic dipole transition are obtained and compared with the experimental data avail-able.For most cases,good agreements are achieved and the relative differences of them are less than 0.114%,8.43% and 9.80%,respectively.The scaling laws of the fine structure splitting and transition rate are obtained on the isoelec-tronic sequence and the corresponding physical mechanisms are discussed.The data sets for tables are openly available at https://www.doi.org/10.57760/sciencedb.j00113.00022.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11704398 and 11934014)the National Key Research and Development Program of China(Grant No.2017YFA0304402)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB21030300)。
文摘Highly charged nickel ions have been suggested as candidates for the ultra-precise optical clock, meanwhile the relevant experiment has been carried out. In the framework of the multiconfiguration Dirac–Hartree–Fock(MCDHF)method, we calculated the hyperfine interaction constants, the Landég-factors, and the electric quadrupole moments for the low-lying states in the 61Ni11+,61Ni12+,61Ni14+, and61Ni15+ ions. These states are clock states of the selected clock transitions in highly charged nickel ions(see Fig. 1). Based on discussing the effects of the electron correlations, the Breit interaction, and quantum electrodynamics(QED) effect on these physical quantities, reasonable uncertainties were obtained for our calculated results. In addition, the electric quadrupole frequency shifts and the Zeeman frequency shifts of the clock transitions concerned were analyzed.
基金National Natural Science Foundation of China(11320101003,11204243)Scientific Research Foundation of Physics of CPEE NWNU~~
文摘铜原子能级结构的理论计算具有非常大的挑战性。本文基于多组态Dirac-Hartree-Fock(MCDHF)方法和相对论组态相互作用(RCI)方法,通过三个大规模的关联模型计算了单激发态3d^104p2P1/2、双激发态3d94s(3D)5s4D3/2,1/2,3d94s(3D)5s2D3/2,3d94s(1D)5s2D3/2以及离子态3d101S0能级和波函数。结果表明,铜原子能级结构对有限组态空间的选择极其敏感,双激发态3d94s(3D)5s4D3/2,1/2,3d94s(3D)5s2D3/2,3d94s(1D)5s2D3/2和离子态3d101S0与单激发态之间的能量差相对于已有实验结果均存在大约-0.4 e V的偏差,而计算得到的共振电子能量与实验结果符合得较好。此外,根据辐射跃迁矩阵元和非辐射跃迁矩阵元计算了双激发态的Fano参数q,并基于Fano理论得到了铜单激发态3d^104p2P1/2的总光电离截面,该理论考虑了直接光电离与光激发自电离之间的干涉效应,即共振3d94s(3D)5s4D3/2,1/2、3d94s(3D)5s2D3/2和3d94s(1D)5s2D3/2具有明显的非对称的Fano轮廓,表明光电离过程与光激发自电离过程之间的干涉对双激发态共振附近的光电离截面轮廓有着极其重要的影响。
