Atomic properties of Cd-like and Sn-like ions for the development of frequency standards and search for the variation of the fine-structure constant

A high-precision relativistic calculations of Cd-like Nd¹²⁺, Sm¹⁴⁺ and Sn-like Pr⁹⁺, Nd¹⁰⁺ atomic properties is carried out using an approach that combines configuration interaction and a linearized coupled-cluster method. These ions have long-lived metastable states with transitions accessible by laser excitations, relatively simple electronic structure, high sensitivity to α variation, and stable isotopes. Breit and QED corrections were included into the calculations. Energies, transition wavelengths, electric- and magnetic-multipole reduced matrix elements, lifetimes, and sensitivity coefficients q and K to the variation of the fine-structure constant α were obtained. A detailed study of uncertainties was performed. Energies for similar Cd-like Ba⁸⁺, La⁹⁺, Ce¹⁰⁺, Pr¹¹⁺ and Sn-like Ba⁶⁺ ions were calculated and compared with experiment for further tests of the accuracy.