Energy levels,oscillator strengths,and radiative rates for Si-like Zn XVII,Ga XVIII,Ge XIX,and As XX

The energy levels, oscillator strengths, line strengths, and transition probabilities for transitions among the terms belonging to the 3s²3p², 3s3p³, 3s²3p3d, 3s²3p4s, 3s²3p4p and 3s²3p4d configurations of silicon-like ions (Zn XVII, Ga XVIII, Ge XIX, and As XX) have been calculated using the configuration-interaction code CIV3. The calculations have been carried out in the intermediate coupling scheme using the Breit–Pauli Hamiltonian. The present calculations have been compared 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 have also been calculated.     

Electron-impact-excitation collision strengths for Be-like ions: II. Intermediate-energy region and collision rates

Intermediate-energy collision strengths calculated using the R-matrix method are presented for four Be-sequence ions, C III (2.6–8.0 Ry), O V (4.4–12.0 Ry), Ne VII (8.4–20.0 Ry), and Si XI (11.0–34.0 Ry). The six ionic states (2s²) ¹S, (2s2p)³P⁰, ¹P⁰ and (2p²)³P^e, ¹D^e, ¹S^e, corresponding to ten fine-structure levels, are included, leading to 29 independent transitions per ion. High-energy analytical expressions have also been calculated for the collision strengths. These results have been combined with previously published low-energy collision strengths to deduce effective collision strengths (that is, collision rates) for ranges of electron temperature appropriate to the four ions.     

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/.     

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.     

Energy levels, transition probabilities, and electron impact excitation collision strengths for Xe XXVII

The energy levels, spontaneous radiative decay rates, and electron impact collision strengths are calculated for Xe XXVII. The data refer to 107 fine-structure levels belonging to the configurations (1s²2s²2p⁶)3s²3p⁶3d¹⁰, 3s²3p⁶3d⁹4l, 3s²3p⁵3d¹⁰4l and 3s3p⁶3d¹⁰4l (l = s, p, d, f). The collision strengths are calculated with a grid of 20 collision energies between 10 and 1500 eV in terms of the energy of the scattered electron, by using the distorted-wave approximation. Effective collision strengths are obtained at six temperatures, T_e (eV) = 10, 100, 300, 500, 800 and 1500, by integrating the collision strengths over a Maxwellian electron distribution. Coupled with these atomic data, a hydrodynamic code MED103 can be used to simulate the Ni-like Xe X-ray laser.     

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,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 and radiative rates for transitions in Ga XXIV

Energy levels, transition probabilities, oscillator strengths, line strengths, and lifetimes have been calculated for Oxygen-like Gallium, Ga XXIV. The configurations 2s²2p⁴, 2s2p⁵, 2p⁶, 2s2p⁴3?, 2s²2p³3?, and 2p⁵3? were used in calculations and 226 fine-structure levels were obtained. The fully relativistic GRASP code has been adopted, and results are reported for all electric dipole (E1), electric quadrupole (E2), magnetic dipole (M1), and magnetic quadrupole (M2) transitions among the lowest 226 levels of Ga XXIV, belonging to the n≤3 configurations. Comparisons have been made with earlier available theoretical and experimental results.     

Energy levels and radiative rates for transitions in B-like to F-like Xe ions (Xe L-XLVI)

Energy levels, radiative rates, oscillator strengths, line strengths, and lifetimes have been calculated for transitions in B-like to F-like Xe ions, Xe L-XLVI. For the calculations, a fully relativistic grasp code has been adopted, and results are reported for all electric dipole, electric quadrupole, magnetic dipole, and magnetic quadrupole transitions among the lowest 125, 236, 272, 226, and 113 levels of Xe L, Xe XLIX, Xe XLVIII, Xe XLVII, and Xe XLVI, respectively, belonging to the n ? 3 configurations.     

Energy levels and radiative rates for transitions in B-like to F-like Kr ions (Kr XXXII-XXVIII)

Energy levels, radiative rates, oscillator strengths, line strengths, and lifetimes have been calculated for transitions in B-like to F-like Kr ions, Kr XXXIII-XXVIII. For the calculations, the fully relativistic GRASP code has been adopted, and results are reported for all electric dipole (E1), electric quadrupole (E2), magnetic dipole (M1), and magnetic quadrupole (M2) transitions among the lowest 125, 236, 272, 226, and 113 levels of Kr XXXII, Kr XXXI, Kr XXX, Kr XXIX, and Kr XXVIII, respectively, belonging to the n ? 3 configurations. Comparisons are made with earlier available theoretical and experimental results, and some discrepancies have been noted and explained.     

Energy levels and radiative rates for transitions in Mg-like iron, cobalt and nickel

Energy levels and radiative rates for electric dipole (E1) transitions among the lowest 141 levels of the (1s²2s²2p⁶) 3?², 3?3?′, and 3?4? configurations of Fe XV, Co XVI, and Ni XVII are calculated through the CIV3 code using extensive configuration-interaction (CI) wavefunctions. The important relativistic effects are included through the Breit-Pauli approximation. In order to keep the calculated energy splittings close to the experimental values, we have made small adjustments to the diagonal elements of the Hamiltonian matrices. The energy levels, including their orderings, are in excellent agreement with the available experimental results for all three ions. However, experimental energies are only available for a few levels. Since mixing among some levels is found to be very strong, it becomes difficult to identify these uniquely. Additionally, some discrepancies with other theoretical work (particularly for Ni XVII) are very large. Therefore, in order to confirm the level ordering as well as to assess the accuracy of energy levels and radiative rates, we have performed two other independent calculations using the GRASP and FAC codes. These codes are fully relativistic, but the CI in the calculations is limited to the basic (minimum) configurations only. This enables us to assess the importance of including elaborate CI for moderately charged ions. Additionally, we report results for electric quadrupole (E2), magnetic dipole (M1), and magnetic quadrupole (M2) transitions, and list lifetimes for all levels. Comparisons are made with other available experimental and theoretical results, and the accuracy of the present results is assessed.     

Energy levels and radiative transition rates for Ge XXXI,As XXXII,and Se XXXIII

Fine-structure energies of the 67 levels belonging to the 1s², 1s 2l$l$, 1s3l$l$, 1s4l$l$, 1s5l$l$, and 1s6l$l$ configurations of Ge XXXI, As XXXII, and Se XXXIII have been calculated using the General-Purpose Relativistic Atomic Structure Package. In addition, radiative rates, oscillator strengths, transition wavelengths, and line strengths have been calculated for all electric dipole, magnetic dipole, electric quadrupole, and magnetic quadrupole transitions among these levels. Lifetimes are also presented for all excited levels of these three ions. We have compared our results with the results available in the literature and the accuracy of the data is assessed. We predict new energy levels, oscillator strengths, and transition probabilities where no other theoretical or experimental results are available, which will form the basis for future experimental work.     

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.     

Electron-impact collision strengths for inner-shell excitation of doubly excited levels from singly excited levels in He-like ions

A simple Coulomb-Born-Exchange method has been used to calculate electron-impact colision strengths for inner-shell excitation of the doubly excited levels with n = 2 in He-like ions from the singly excited levels. The results are of particular interest for plasma diagnostic purposes. The calculations were made for nine impact electron energies in threshold units ? = 1.0, 1.2, 1.5, 1.9, 2.5, 4.0, 6.0, 10.0 and 15.0 for 19 He-like ions with nuclear charge number Z in the range 6 ≤ Z ≤ 74. Fits are given of the scaled collision strength $\text{Z}{}^2\text{Ω}$ to simple functions of ? that are readily integrated over a Maxwellian distribution to obtain collision rates. Configuration-interaction and intermediate-coupling effects have been included in the calculations. Calculated values for transition energies and radiative line strengths are also given.     

Fine-structure calculations of energy levels, oscillator strengths, and transition probabilities for sodium-like ions (Co XVII-Kr XXVI)

We have calculated fine-structure energy levels, oscillator strengths and transition probabilities for transitions among the terms belonging to the 1s²2s²2p⁶ns (²S), 1s²2s²2p⁶np (²P), 1s²2s²2p⁶nd (²D) (n = 3, 4, 5), and 1s²2s²2p⁶nf (²F) (n = 4, 5) configurations. The calculations are based upon the general configuration-interaction code CIV3 of Hibbert which uses orthonormal orbitals of radial functions expressed as superpositions of normalized Slater-type orbitals. Our calculated values are compared with experimental and other theoretical results where a satisfactory agreement is found. We also report on some unpublished energy values and oscillator strengths.     

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.     

Intermediate-coupling collision strengths for transitions between doubly excited levels produced by electron impact on highly charged He-like ions

Coulomb-Born-Exchange data for intermediate-coupling scaled collision strengths $\text{Z}{}^2\text{Ω}$ for fine-structure transitions of type 2l_a2l_b^2S_a+1L_aja?2l_a2l′_b^2S′_a+1L′_aj′a or 2l_a2l_b(j_aj_b)_Ja?2l_a2l′_b(j′_aj′_b)_J′a between the doubly excited levels in He-like ions with 6 ≤ Z ≤ 74 are fitted by simple functions of the impact-electron energy ? in threshold units. To obtain collision rates these functions can be readily integrated over a Maxwellian energy-distribution function for the electrons. Fits to the data for transitions between energy terms are also included. In addition results are given for the transition energies and electric-dipole radiative line strengths. The basic collision-strength data cover impact-electron energies $\text{≤}\text{3.25Z}{}^2\text{Ry}$ or 44.2Z² eV.     

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.