Atomic radiative data such as excitation energies, transition wavelengths, radiative rates, and level lifetimes with high precision are the essential parameters for the abundance analysis, simulation, and diagnostics ...Atomic radiative data such as excitation energies, transition wavelengths, radiative rates, and level lifetimes with high precision are the essential parameters for the abundance analysis, simulation, and diagnostics in fusion and astrophysical plasmas. In this work, we mainly focus on reviewing our two projects performed in the past decade. One is about the ions with Z■30 that are generally of astrophysical interest, and the other one is about the highly charged krypton(Z = 36)and tungsten(Z = 74) ions that are relevant in research of magnetic confinement fusion. Two different and independent methods, namely, multiconfiguration Dirac–Hartree–Fock(MCDHF) and the relativistic many-body perturbation theory(RMBPT) are usually used in our studies. As a complement/extension to our previous works for highly charged tungsten ions with open M-shell and open N-shell, we also mainly focus on presenting and discussing our complete RMBPT and MCDHF calculations for the excitation energies, wavelengths, electric dipole(E1), magnetic dipole(M1), electric quadrupole(E2), and magnetic quadrupole(M2) transition properties, and level lifetimes for the lowest 148 levels belonging to the 3l3configurations in Al-like W61+. We also summarize the uncertainties of our systematical theoretical calculations, by cross-checking/validating our datasets from our RMBPT and MCDHF calculations, and by detailed comparisons with available accurate observations and other theoretical calculations. The data are openly available in Science Data Bank at https://doi.org/10.57760/sciencedb.10569.展开更多
It is shown that the 3d5(4X) 4s(5X)of 4s satellites ,except to the coupling between 3d54s(7,5S) and 3p→ 3d transition ,plays a key role on the magnitude of photoionization of 4s cross section .The coupled equation me...It is shown that the 3d5(4X) 4s(5X)of 4s satellites ,except to the coupling between 3d54s(7,5S) and 3p→ 3d transition ,plays a key role on the magnitude of photoionization of 4s cross section .The coupled equation methodis improvedto calculate this resonance by including these channels .The results of calculations are compared with the experimental data from 4 6eV to 5 6eV photon energies,which are in good agreement with the experiment.展开更多
A photoionization cross section calculation ofMn^＋ is performed in the formalism of many-body perturbation theory for photon energies ranging from 48 eV to 56 eV. We consider excitations from the 3p, 3d, and 4s subsh...A photoionization cross section calculation ofMn^＋ is performed in the formalism of many-body perturbation theory for photon energies ranging from 48 eV to 56 eV. We consider excitations from the 3p, 3d, and 4s subshells. The effects of the strong 3p→ 3d and 3p→ 4s transitions are included as resonant contributions to the total cross sections. Good agreement with experiment is found.展开更多
Electronic band structure is one of the most important intrinsic properties of a material,and is in particular crucial in electronic,photo-electronic and photo-catalytic applications.Kohn-Sham Density-functional theor...Electronic band structure is one of the most important intrinsic properties of a material,and is in particular crucial in electronic,photo-electronic and photo-catalytic applications.Kohn-Sham Density-functional theory(KS-DFT)within currently available local or semi-local approximations to the exchange-correlation energy functional is problematic for the description of electronic band structure.Many-body perturbation theory based on Green’s function(GF)provides a rigorous framework to describe excited-state properties of materials.The central ingredient of the GF-based many-body perturbation theory is the exchangecorrelation self-energy,which accounts for all nonclassical electron-electron interaction effects beyond the Hartree theory,and formally can be obtained by solving a set of complicated integro-differential equations,named Hedin’s equations.The GW approximation,in which the self-energy is simply a product of Green’s function and the screened Coulomb interaction(W),is currently the most accurate first-principles approach to describe electronic band structure properties of extended systems.Compared to KS-DFT,the computational efforts required for GW calculations are much larger.Various numerical techniques or approximations have been developed to apply GW for realistic systems.In this paper,we give an overview of the theory of first-principles Green’s function approach in the GW approximation and review the state of the art for the implementation of GW in different representations and with different treatment of the frequency dependence.It is hoped that further methodological developments will be inspired by this work so that the approach can be applied to more complicated and scientifically more interesting systems.展开更多
基金the support from the National Natural Science Foundation of China (Grant Nos. 12074081 and 12104095)。
文摘Atomic radiative data such as excitation energies, transition wavelengths, radiative rates, and level lifetimes with high precision are the essential parameters for the abundance analysis, simulation, and diagnostics in fusion and astrophysical plasmas. In this work, we mainly focus on reviewing our two projects performed in the past decade. One is about the ions with Z■30 that are generally of astrophysical interest, and the other one is about the highly charged krypton(Z = 36)and tungsten(Z = 74) ions that are relevant in research of magnetic confinement fusion. Two different and independent methods, namely, multiconfiguration Dirac–Hartree–Fock(MCDHF) and the relativistic many-body perturbation theory(RMBPT) are usually used in our studies. As a complement/extension to our previous works for highly charged tungsten ions with open M-shell and open N-shell, we also mainly focus on presenting and discussing our complete RMBPT and MCDHF calculations for the excitation energies, wavelengths, electric dipole(E1), magnetic dipole(M1), electric quadrupole(E2), and magnetic quadrupole(M2) transition properties, and level lifetimes for the lowest 148 levels belonging to the 3l3configurations in Al-like W61+. We also summarize the uncertainties of our systematical theoretical calculations, by cross-checking/validating our datasets from our RMBPT and MCDHF calculations, and by detailed comparisons with available accurate observations and other theoretical calculations. The data are openly available in Science Data Bank at https://doi.org/10.57760/sciencedb.10569.
文摘It is shown that the 3d5(4X) 4s(5X)of 4s satellites ,except to the coupling between 3d54s(7,5S) and 3p→ 3d transition ,plays a key role on the magnitude of photoionization of 4s cross section .The coupled equation methodis improvedto calculate this resonance by including these channels .The results of calculations are compared with the experimental data from 4 6eV to 5 6eV photon energies,which are in good agreement with the experiment.
基金The project supported by the Research Fund for the Doctoral Program of Higher Education under Grant No. 2002610001 and the National Natural Science Foundation of China under Grant No. 60054402
文摘A photoionization cross section calculation ofMn^＋ is performed in the formalism of many-body perturbation theory for photon energies ranging from 48 eV to 56 eV. We consider excitations from the 3p, 3d, and 4s subshells. The effects of the strong 3p→ 3d and 3p→ 4s transitions are included as resonant contributions to the total cross sections. Good agreement with experiment is found.
文摘Electronic band structure is one of the most important intrinsic properties of a material,and is in particular crucial in electronic,photo-electronic and photo-catalytic applications.Kohn-Sham Density-functional theory(KS-DFT)within currently available local or semi-local approximations to the exchange-correlation energy functional is problematic for the description of electronic band structure.Many-body perturbation theory based on Green’s function(GF)provides a rigorous framework to describe excited-state properties of materials.The central ingredient of the GF-based many-body perturbation theory is the exchangecorrelation self-energy,which accounts for all nonclassical electron-electron interaction effects beyond the Hartree theory,and formally can be obtained by solving a set of complicated integro-differential equations,named Hedin’s equations.The GW approximation,in which the self-energy is simply a product of Green’s function and the screened Coulomb interaction(W),is currently the most accurate first-principles approach to describe electronic band structure properties of extended systems.Compared to KS-DFT,the computational efforts required for GW calculations are much larger.Various numerical techniques or approximations have been developed to apply GW for realistic systems.In this paper,we give an overview of the theory of first-principles Green’s function approach in the GW approximation and review the state of the art for the implementation of GW in different representations and with different treatment of the frequency dependence.It is hoped that further methodological developments will be inspired by this work so that the approach can be applied to more complicated and scientifically more interesting systems.
