Relativistic equation-of-motion coupled-cluster theory analysis of black-body radiation shift in the clock transition of Zn I

We have employed equation-of-motion coupled-cluster (EOM-CC) method in the four-component relativistic theory framework to understand roles of electron correlation effects in the $\mathit{\text{ab}}\mathit{\text{initio}}$ estimations of electric dipole polarizabilities ($\alpha$) of the states engaged in the clock transition (${}^1$S${}_0$$\to$${}^3$P${}_0$) of the zinc atom. Roles of basis size, inclusion of higher-level excitations, and higher-order relativistic effects in the evaluation of both excitation energies of a few low-lying excited states and $\alpha$ are analyzed systematically. Our EOM-CC values are compared with the earlier reported theoretical and experimental results. This demonstrates the capability of the EOM-CC method to ascertain the preciseness of the black-body radiation shift in a clock transition, which holds paramount importance for optical clock-based experiments.