Energies and oscillator strengths for allowed transitions in S V,Cl VI and Fe XV

We present calculations using configuration interaction wave functions of energies and oscillator strengths for allowed transitions between states of the form 3l3l′ or 3l4l′ in S V, Cl VI and Fe XV. For the first two ions, LS coupling has been used throughout, but corrections incorporating experimental energies are made to the wave functions. For Fe XV, mass correction and Darwin terms are added to the Hamiltonian. These substantially improve the agreement between calculated and experimental energies. Some previously undetermined energy levels in Fe XV are predicted.     

Excitation energies and oscillator strengths in Al-, Si-, and P-like ions

Theoretical energy levels and transition probabilities are calculated for low-lying levels of aluminum-, silicon-, and phosphorus-like ions from Z = 13 to Z = 106. The multiconfiguration Dirac-Fock technique is used to obtain energy levels and wave functions. Electron correlation effects are accounted for by including many electronic configurations in the self-consistent-field procedure. Contributions from the Breit interaction and the Lamb shift are treated as a first-order perturbation. The electric-dipole, electric-quadrupole, and magnetic-dipole transitions between levels are also calculated.     

Theoretical transition probabilities, oscillator strengths, and radiative lifetimes of levels in Pb IV

Transition probabilities and oscillator strengths of 176 spectral lines with astrophysical interest arising from 5d¹⁰ns (n = 7,8), 5d¹⁰np (n = 6,7), 5d¹⁰nd (n = 6,7), 5d¹⁰5f, 5d¹⁰5g, 5d¹⁰nh (n =  6,7,8), 5d⁹6s², and 5d⁹6s6p configurations, and radiative lifetimes for 43 levels of Pb IV, have been calculated. These values were obtained in intermediate coupling (IC) and using relativistic Hartree-Fock calculations including core-polarization effects. For the IC calculations, we use the standard method of least-square fitting from experimental energy levels by means of the Cowan computer code. The inclusion in these calculations of the 5d¹⁰7p and 5d¹⁰5f configurations has facilitated a complete assignment of the energy levels in the Pb IV. Transition probabilities, oscillator strengths, and radiative lifetimes obtained are generally in good agreement with the experimental data.     

Transition probabilities and oscillator strengths of E1 transitions in Fe XII and Fe XIV

Non-orthogonal orbitals in the multiconfiguration Hartree-Fock approach are used to calculate line strengths, oscillator strengths and transition probabilities for E1 transitions among the fine-structure levels of the 3s²3p³, 3s3p⁴, 3s²3p²3d, 3s3p³3d, 3p⁵ and 3s²3p3d² configurations in Fe XII and 3s²3p, 3s3p², 3s²3d, 3p³, 3s3p3d, 3p²3d, 3s3d², 3p3d², 3s²4s, 3s²4p, 3s3p4s and 3s²4d configurations in Fe XIV. The lifetimes of excited levels belonging to these configurations of Fe XII and Fe XIV are also presented. An accurate representation of the levels has been obtained using spectroscopic and correlation radial functions. The wavefunctions exhibit large correlations and significant dependence of one-electron valence orbitals due to both the total and intermediate terms. The relativistic corrections are included through the one-body and two-body operators in the Breit-Pauli Hamiltonian. Progressively larger calculations are performed to check for important electron correlation contributions and for convergence of results. The atomic wavefunctions give excitation energies which are in close agreement with experiment. The present oscillator strengths and transition probabilities compare very well with previous large scale calculations.     

Energy levels,radiative rates,and lifetimes for transitions in W XL

Energy levels and radiative rates are reported for transitions in Br-like tungsten, W XL, calculated with the general-purpose relativistic atomic structure package (grasp). Configuration interaction (CI) has been included among 46 configurations (generating 4215 levels) over a wide energy range up to 213 Ryd. However, for conciseness results are only listed for the lowest 360 levels (with energies up to ∼43 Ryd), which mainly belong to the 4s²4p⁵,4s²4p⁴4d,4s²4p⁴4f,4s4p⁶,4p⁶4d,4s4p⁵4d,4s²4p³4d², and 4s²4p³4d4f configurations, and provided for four types of transitions, E1, E2, M1, and M2. Comparisons are made with existing (but limited) results. However, to fully assess the accuracy of our data, analogous calculations have been performed with the flexible atomic code, including an even larger CI than in grasp. Our energy levels are estimated to be accurate to better than 0.02 Ryd, whereas results for radiative rates (and lifetimes) should be accurate to better than 20% for a majority of the strong transitions.     

Energy levels,radiative rates,and lifetimes for transitions in W LVIII

Energy levels and radiative rates are reported for transitions in Cl-like W LVIII. Configuration interaction (CI) has been included among 44 configurations (generating 4978 levels) over a wide energy range up to 363 Ryd, and the general-purpose relativistic atomic structure package (grasp) adopted for the calculations. Since no other results of comparable complexity are available, calculations have also been performed with the flexible atomic code (fac), which help in assessing the accuracy of our results. Energies are listed for the lowest 400 levels (with energies up to ∼98 Ryd), which mainly belong to the 3s²3p⁵, 3s3p⁶, 3s²3p⁴3d, 3s²3p³3d², 3s3p⁴3d², 3s²3p²3d³, and 3p⁶3d configurations, and radiative rates are provided for four types of transitions, i.e. E1, E2, M1, and M2. Our energy levels are assessed to be accurate to better than 0.5%, whereas radiative rates (and lifetimes) should be accurate to better than 20% for a majority of the strong transitions.     

Energy levels, oscillator strengths and transition probabilities for Si-like P II, S III, Cl IV, Ar V and K VI

Fine-structure calculations of energy levels, oscillator strengths, and transition probabilities for transitions among the terms belonging to 3s²3p², 3s3p³, 3s²3p3d, 3s²3p4s, 3s²3p4p, 3s²3p4d, 3s²3p5s and 3s²3p5p configurations of silicon-like ions P II, S III, Cl IV, Ar V and K VI have been calculated using configuration-interaction version 3 (CIV3). We compared our data with the available experimental data and other theoretical calculations. Most of our calculations of energy levels and oscillator strengths (in length form) show good agreement with both experimental and theoretical data. Lifetimes of the excited levels are also given.     

Wavelengths,transition probabilities,and oscillator strengths for M-shell transitions in Co-, Ni-, Cu-, Zn-, Ga-, Ge-, and Se-like Au ions

Wavelengths, transition probabilities, and oscillator strengths have been calculated for M-shell electric dipole transitions in Co-, Ni-, Cu-, Zn-, Ga-, Ge-, and Se-like Au ions. The fully relativistic multiconfiguration Dirac–Fock method, taking quantum electrodynamical effects and the Breit correction into account, was used in the calculations. Calculated energy levels of M-shell excited states for Cu-, Zn-, Ga-, Ge-, and Se-like Au ions from the method were compared with available theoretical and experimental results, and good agreement with them was achieved.     

Calculated wavelengths,oscillator strengths,and energy levels for n = 2−2 and 2–3 transitions in F-like ions Mg IV to Ni XX and for 3−3 and other transitions in Mg IV,Al V,and Si VI

Weighted oscillator strengths, energy levels, and wavelengths are calculated for the 2s²2p⁵-2s2p⁶, 2s²2p⁵-2²2p⁴3s, and 2s²2p⁵-2s²2p⁴3d transition arrays for F-like ions in the isoelectronic sequence from Mg IV to Ni XX and in addition for n = 3?3 and other transitions in Mg IV, Al V, and Si VI. The calculation involves the computation of ab initio values of Slater radial energy integrals using a Hartree-Fock-Relativistic computer program package, which includes configuration-interaction and applies the Blume-Watson method for spin-orbit integrals. Some of the parameters are subsequently optimized on the basis of empirical data. Adopted values are tabulated along with atomic energy level compositions.     

Electron impact collision strengths and oscillator strengths for Ni-like Nd, Sm, Eu, Gd, Ta, and W ions

Energy levels, oscillator strengths, and electron impact collision strengths have been calculated for Ni-like ions of Nd (Z = 60), Sm (Z = 62), Eu (Z = 63), Gd (Z = 64), Ta (Z = 73), and W (Z = 74) among the 249 levels belonging to the ([Ne])3s²3p⁶3d¹⁰, 3s²3p⁶3d⁹nl, 3s²3p⁵3d¹⁰nl, 3s3p⁶3d¹⁰nl (n = 4, 5; l = 0, 1, … , n − 1) configurations. Configuration interactions among these configurations have been included in the calculations. Collision strengths have been obtained at 20 scattered electron energies (5–20,000 eV) and they have been listed at six representative energies of 100, 400, 1000, 2500, 5000, and 10,000 eV in this work. Effective collision strengths have been obtained by assuming a Maxwellian electron velocity distribution at 24 temperatures ranging from 100 to 3000 eV. Our results are compared with those available in the literature. The relative difference is within 0.3% between our calculated energy levels and the corresponding experimental values wherever available. The energy levels are expected to be be accurate within 0.6%, while oscillator strengths and collision strengths for strong transitions are probably accurate to better than 20%. The complete dataset is available electronically from http://www.astronomy.csdb.cn/EIE/.     

Electron impact collision strengths and oscillator strengths for Ge-, Ga-, Zn-, Cu-, Ni-, and Co-like Au ions

Energy levels, oscillator strengths, and electron impact collision strengths have been calculated for Ge-, Ga-, Zn-, Cu-, Ni-, and Co-like Au ions. For Ni-like Au, these atomic data are obtained among the levels belonging to the configurations of ([Ne])3s²3p⁶3d¹⁰, 3s²3p⁶3d⁹nl, 3s²3p⁵3d¹⁰nl, and 3s 3p⁶3d¹⁰nl (n = 4, 5; l = 0, 1, … , n − 1). For other Au ions, more levels have been obtained with special attention to atomic data up to transitions of 5f → 3d for emission or 3d → 5f for absorption. Configuration interactions are taken into account for all levels included. Collision strengths have been obtained at 20 scattered electron energies (5-40,000 eV) and they are listed at six representative energies of 100, 500, 1000, 5000, 10,000, and 20,000 eV in this work. Effective collision strengths have been obtained by assuming a Maxwellian electron velocity distribution at 10 representative temperatures ranging from 500 to 5000 eV. The present dataset should be adequate for most applications. The energy levels are expected to be accurate to within 0.5%, while oscillator strengths and collision strengths for strong transitions are probably accurate to better than 20%. The complete dataset is available electronically from http://www.astronomy.csdb.cn/EIE/.     

Weighted oscillator strengths for the Xe IV spectrum

The weighted oscillator strengths, gf, of 769 previously reported classified spectral lines, and 49 new observed and also classified lines belonging to the 5s²5p³, 5s5p⁴, 5s²5p²(6p + 4f), and 5s²5p²(5d + 6s) transitions array in Xe IV, were determined through a multiconfigurational Hartree-Fock relativistic approach. In this calculation, the electrostatic parameters were optimized by a least-square procedure in order to improve the adjustment to experimental energy levels.     

Oscillator strengths and radiative rates for transitions in neutral sulfur

We present accurate oscillator strengths and radiative rates for 2173 E1 transitions among the 120 levels belonging to 3s²3p⁴, 3s3p⁵, and 3s²3p³(⁴S^o,²D^o,²P^o)n? configurations where . A configuration interaction approach is employed through the standard CIV3 program. The 114 LS states included in the present calculation generate 250 fine-structure levels belonging to the above configurations below 100,000 cm⁻¹. However, results of only 120 fine-structure levels are presented due to the absence of experimental energy values for the remaining levels. Tabulations of oscillator strengths and radiative rates, and their comparison with other calculations, are presented in the first two tables. In a separate table the oscillator strengths and transition probabilities, in length and velocity gauges, are presented for 2173 E1 transitions, and are arranged in ascending order of wavelength.     

Energy levels,oscillator strengths,radiative decay rates,and fine-structure collision strengths for the Zn-like ions Nb XII and Mo XIII

Energy levels, line strengths, oscillator strengths, radiative decay rates, and fine-structure collision strengths are presented for the Zn-like ions Nb XII and Mo XIII. The atomic data are calculated with the AUTOSTRUCTURE code, where relativistic corrections are introduced according to the Breit–Pauli distorted wave approach. We present the calculations of atomic data for 110 fine-structure levels generated from fifteen configurations (1s²2s²2p⁶3s²3p⁶3d¹⁰)4s², 4s4p, 4p², 4s4d, 4s4f, 4s5s, 4p4d, 4s5p, 4s5d, 4p4f, 4p5s, 4d², 4d4f, 4f², and 3d⁹4s²4p. Fine-structure collision strengths for transitions from the ground and the first four excited levels are presented at six electron energies (20, 50, 80, 110, 150, and 180 Ryd). Our atomic structure data are compared with the available experimental and theoretical results.     

Oscillator strengths of allowed transitions for O III

The electric dipole oscillator strengths for lines in O III between some singlet and triplet levels have been calculated using the weakest bound electron potential model theory and the quantum defect orbital theory. In the calculations, both multiplet and fine-structure transitions are studied. The calculated oscillator strengths have been compared with available theoretical and experimental results. Good agreement with results in the literature has been obtained.     

Relativistic oscillator strengths in the boron isoelectronic sequence

Oscillator strengths for electric dipole transitions, between states of the ground complex of the boron isoelectronic sequence up to Z = 93, are studied by means of relativistic wave functions obtained from a central field model. A graphical representation for 45 transitions is presented and the results are analyzed by means of the relativistic Z-dependent theory of Layzer and Bahcall. In the intermediate Z-region anticrossing effects appear which cause some irregularities in the behavior of the oscillator strengths.     

Calculated oscillator strengths and wavelengths for allowed transitions within the third shell for ions in the Mg-like isoelectronic sequence between S V and Ni XVII

Weighted oscillator strengths, energy levels, and wavelengths are calculated for the 3s²-3s3p, 3s3p-3p², 3s3p-3s3d, 3p²-3p3d, and 3s3d-3p3d transition arrays for Mg-like ions in the sequence from S V to Ni XVII. Their values are tabulated along with Slater radial integrals, Racah reduced radial dipole matrix elements, and level compositions. The theoretical procedure involves the computation of ab initio values for the Slater radial energy integrals and their subsequent optimization in accordance with dependent measured wavelengths. Published energy levels are improved on the basis of new calculations of wavelengths of the 3s²¹S₀-3s3p³P₁ intercombination lines. Observational wavelength and energy-level data are tabulated.     

Optical oscillator strengths, mean excitation energy, shell corrections and experimental values for stopping power

In a recent paper, Smith, Inokuti, Karstens and Shiles discussed optical oscillator strengths (OOS) of graphite, Al and Si and compared the mean excitation energy I obtained by integration to that from stopping power measurements. They found agreement for graphite and Al, but disagreement for Si. In this paper, we discuss the OOS of Al, Si, Cu and Au and compare the stopping powers calculated from these OOS (or from a single I-value), using program CasP40, directly to experimental stopping power values for protons between 10 and 80 MeV. We find that the choice of proper shell corrections is essential: since the shell correction built into CasP is too small, we take the correction for Al, Si and Cu from the BEST program of Berger and Bichsel. For Au, better results are obtained using Bonderup’s shell correction. With these choices, we find fair agreement between experimental and calculated stopping data, both with the I-values from ICRU Report 49 and with OOS. Even in the case of Si, the stopping curve based on OOS is not in conflict with experimental data. In all cases, the curves calculated using SRIM are in good agreement with the data.     

Fine-structure calculations of energy levels,oscillator strengths,and transition probabilities for sulfur-like iron,Fe XI

Energy levels, oscillator strengths, and transition probabilities for transitions among the 14 LS states belonging to configurations of sulfur-like iron, Fe XI, have been calculated. These states are represented by configuration interaction wavefunctions and have configurations 3s²3p⁴, 3s3p⁵, 3s²3p³3d, 3s²3p³4s, 3s²3p³4p, and 3s²3p³4d, which give rise to 123 fine-structure energy levels. Extensive configuration interaction calculations using the CIV3 code have been performed. To assess the importance of relativistic effects, the intermediate coupling scheme by means of the Breit–Pauli Hamiltonian terms, such as the one-body mass correction and Darwin term, and spin–orbit, spin–other-orbit, and spin–spin corrections, are incorporated within the code. These incorporations adjusted the energy levels, therefore the calculated values are close to the available experimental data. Comparisons between the present calculated energy levels as well as oscillator strengths and both experimental and theoretical data have been performed. Our results show good agreement with earlier works, and they might be useful in thermonuclear fusion research and astrophysical applications.