MCDHF and RCI calculations of energy levels, lifetimes, and transition rates in Si III and Si IV

Abstract

We present extensive multiconfiguration Dirac-Hartree-Fock and relativistic configuration interaction calculations including 106 states in doubly ionized silicon (Si iii) and 45 states in triply ionized silicon (Si iv), which are important for astrophysical determination of plasma properties in different objects. These calculations represents an important extension and improvement of earlier calculations especially for Si iii. The calculations are in good agreement with available experiments for excitation energies, transition properties, and lifetimes. Important deviations from the NIST-database for a selection of perturbed Rydberg series are discussed in detail.

Energy levels and transition data of 3p63d8 and 3p53d9 configurations in Fe-like ions (Z = 57,60,62,64,65)

“…This situation is reasonable and has a precedent, where the authors found that some weaker transitions are composed of two-electron or intercombination lines transitions, the transition rates for this kind of transition are difficult to compute accurately. [61,62]…”

Large-scale multiconfiguration Dirac-Hartree-Fock calculations of atomic data, Landé gj -factors and hyperfine constants of the neutral Rn-211 isotope

“…Atomic data are composed of energy levels, transition rates, and oscillator strengths, whereas hyperfine parameters include the Landé g J -factors, magnetic dipole, and electric quadrupole hyperfine constants. These data are useful for identifying elements in astrophysical objects and modeling astrophysical spectra [7].…”