Coefficients of sensitivity toαvariation for astrophysically relevant transitions in Ni ii

Abstract

We calculated the dependence of the transition frequencies on the fine-structure constant $\ensuremath{\alpha}$ ($q$ factors) for Ni ii. Nickel is one of the few elements with high sensitivity to $\ensuremath{\alpha}$ variation, whose lines are observed at high redshifts. This makes it a sensitive probe for $\ensuremath{\alpha}$ variation on the cosmological time scale. The electronic structure of Ni ii ion was treated within the configuration interaction method using the Dirac-Coulomb Hamiltonian.