Large scale CIV3 calculations of fine-structure energy levels, oscillator strengths, and lifetimes in Fe XIV and Ni XVI

Effects of valence-valence, core-valence, and core-core correlations on the fine-structure energy levels in Al-like ions

“…Predicted data based on measurements has been given by Froese Fischer et al [9], Safronova et al [16], and Vilkas et al [17,18]. Similar data for Fe XIV and Ni XVI were given by Gupta et al [13] and Aggarwal et al [37]. As can be seen in Tables V-IX, our results are in excellent agreement with the predicted data, the difference being 0.01%-1% for most cases.…”

“…Many ab initio calculations using a wide range of different methods * gjiang@scu.edu.cn have also been done for calculating fine-structure energy levels and lifetimes. To mention just a few, fine-structure energy levels in Si II [8] and Al I-Fe XIV [9] have been calculated using the multiconfiguration Hartree-Fock (MCHF) approach, Cl V [10], Mn XIII [11], Co xv [12], Fe XIV, and Ni XVI [13] using CIV3, S IV [14] and Ar VI [15] using configurationinteraction (CI) expansions, P III-Mo XXX [16], Xe XXXXII [17], and Au LXVII [18] using the many-body perturbation theory (MBPT) approach, Ca VIII [19] using the R-matrix approximation, K VII [20] using the multiconfiguration Hartree-Dirac-Fock method (MCDHF) method, and Si II [21] using the relativistic quantum defect orbital (RQDO) method. Both experiment and theory have been used to investigate the fine structure for medium-to low-Z ions.…”

Multireference Møller–Plesset perturbation theory results on levels and transition rates in Al-like ions of iron group elements

“…A second electron in the valence shell introduces massive complications; while experiment can reach the same accuracy as for one-electron spectra, theory has been struggling. Calculations of Al-like ions sometimes have been extensive, but have covered only a single element at a time [3][4][5][6][7][8][9][10][11][12][13][14][15], while others sometimes employed rather few configurations when tabulating results for a full isoelectronic sequence. For calculations of a sequence of ions along the Al sequence, see, for example [16][17][18][19][20][21][22].…”

Transition probabilities and lifetimes of the low-lying levels of Fe XIV

“…For the 4 F 7/2 level, the contributions from dipole-forbidden transitions are completely negligible for its lifetime and are not displayed in this table. The strongest decay path is the spin-allowed 3s3p 2 4 P 5/2 -3s3p( 3 P)3d 4 F 7/2 (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) transition, while the transition rate is higher than that of the 3s3p 2 2 D 5/2 -3s3p( 3 P)3d 4 F 7/2 (7-20) and 3s 2 3d 2 D 5/2 -3s3p( 3 P)3d 4 F 7/2 (12-20) intercombina-tion lines by almost 2 orders of magnitude. It can be seen that our three E1 transition rates are in better agreement with the previous results.…”

“…For example, detailed computations were carried out by Froese Fischer et al [10] for all energy levels and lifetimes within the n = 3 complex of Fe XIV using multiconfiguration Hartree-Fock (MCHF) wavefunctions, as well as by Fawcett on the wavelengths and oscillator strengths of the allowed transitions within the third shell for ions from Cl V to Ni XVI; [11] Huang performed (small-scale) multiconfiguration Dirac-Fock (MCDF) calculations with Breit interaction and quantum electrodynamics (QED) correction for the energy levels and transition probabilities of all the low-lying 40 levels of Fe XIV; [12] Bhatia et al calculated the atomic data for a five-configuration model of Fe XIV using the SUPER-STRUCTURE (SS) code based on a scaled Thomas-Fermi model; [13,14] Storey et al calculated the collision strengths and thermally averaged collision strengths for electron excitation between the forty energetically lowest levels of Fe XIV using the R-matrix method; [15] Gupta et al calculated the fine-structure energy levels, oscillator strengths, and lifetimes for Fe XIV using large-scale CIV3 calculations. [16,17] In addition, Dong et al [18] and Hao et al [19] calculated radiative lifetimes and fine-structure levels of the ions of an aluminum isoelectronic sequence with the MCDF method, respectively. Froese Fischer et al analysed relativistic energy levels, lifetimes, and transition probabilities for the sodium-like to argon-like sequences using the MCHF method.…”