Theoretical Investigation of Energy Levels and Transition Rates for Te IV

A theoretical study of the atomic structure properties of triply ionized tellurium (Te IV) is carried out employing the multiconfiguration Dirac–Hartree–Fock (MCDHF) and relativistic configuration interaction (RCI) methods. Electron correlation effects are systematically taken into account through large configuration state function expansions. The energy levels and transition rates are computed for the 63 lowest states in Te IV. Inclusion of natural orbitals improves the results and leads to closer agreement with experimental values. The present results are compared with spectroscopic data from the National Institute of Standards and Technology (NIST) database and other experimental and theoretical results available. The calculated excitation energies are in good agreement with the experimental data from the NIST database, with a mean absolute relative error of about 0.3%. Electric-dipole (E1) transition rates and weighted oscillator strengths are provided over the wavelength range 409.94–732 580A ̊. Approximately 63% of the E1 transitions are classified as B or better according to the NIST accuracy classes. These accurate and reliable data are useful in the kilonova spectral modeling where atomic data are quite sparse for heavy elements.