Pr¹⁰⁺ as a candidate for a high-accuracy optical clock for tests of fundamental physics.

We propose In-like Pr¹⁰⁺ as a candidate for the development of a high-accuracy optical clock with high sensitivity to a time variation of the fine-structure constant, \dot{α}/α, as well as favorable experimental systematics. We calculate its low-lying energy levels by combining the configuration interaction and the coupled cluster method, achieving uncertainties as low as 0.1%, and improving previous work. We benchmark these results by comparing our calculations for the 5s²5p ²P_1/2 - 5s²5p ²P_3/2 transition in Pr¹⁰⁺ with a dedicated measurement and for Pr⁹⁺ with a recent experiment, respectively. In addition, we report calculated hyperfine-structure constants for the clock and logic states in Pr¹⁰⁺.