We apply a version of the recently developed approach combining the correlation potential, linearized singles-doubles coupled-cluster, and the configuration interaction methods to the spectra of the heavy alkaline earths barium, radium, and element 1
20. Quantum electrodynamics radiative corrections are included. We have found unprecedented agreement between ab initio theory and experiment for the spectra of barium and radium, and we make accurate predictions for missing and unreliable data for all three atoms.
