Relativistic effects in two valence-electron atoms and ions and the search for variation of the fine-structure constant

We perform accurate calculations of the dependence of transition frequencies in two-valence-electron atoms and ions on a variation of the fine-structure constant, α=e²∕c. The relativistic Hartree-Fock method is used with many-body perturbation theory and configuration interaction methods to calculate transition frequencies. The results are to be used in atomic-clock-type laboratory experiments designed to test whether α varies in time.