Multiconfiguration Dirac–Hartree–Fock and Relativistic Many Body Perturbation Theory calculations of energy levels, wavelengths, weighted oscillator strengths, transitions rates, lifetimes, isotope shifts, hyperfine interaction constants and Landé g-factors of Zr XXXIX

Abstract

An extensive and accurate data set of energy levels, wavelengths, weighted oscillator strengths, transitions rates, lifetimes, isotope shifts, hyperfine interaction constants and Landé g-factors have been calculated for the lowest 71 odd and even parity states arising from the 1s2 and 1snl(n=1−6,0≤l≤n−1) configurations of helium-like Zr. Calculations were performed using the Multiconfigurational Dirac–Hartree–Fock​ (MCDHF) followed by the Relativistic Configuration Interaction (RCI) method. Although no measurements or other theoretical results are available for comparison, we have implemented parallel calculations using a Flexible Atomic Code (FAC) by introducing the Relativistic Many-Body Perturbation Theory (RMBPT) method. Transition rates for electric-multipole (dipole (E1), quadrupole (E2)) and magnetic-multipole (dipole (M1), quadrupole (M2)) have been also calculated. Breit interactions and quantum electrodynamics effects (QED) have been included as perturbations in extensive relativistic configuration interaction (RCI) calculations. The results arising from the two sets of calculations MCDHF/RCI and RMBPT are quite close. Almost all atomic data of helium-like Zr ion presented in this paper are calculated for the first time. We expect that our results can be used as a reference point for any further calculations of plasma processes (electron impact excitation, dielectronic recombination). Furthermore, our values can contribute to the NIST database by essentially providing the data for the lowest singly excited states of Zr XXXIX.