  The perturbed relativistic coupled-cluster (PRCC) theory is applied to
calculate the electric dipole polarizabilities of alkaline Earth metal atoms.
The Dirac-Coulomb-Breit atomic Hamiltonian is used and we include the triple
excitations in the relativistic coupled-cluster (RCC) theory. The theoretical
issues related to the triple excitation cluster operators are described in
detail and we also provide details on the computational implementation. The
PRCC theory results are in good agreement with the experimental and previous
theoretical results. We, then, highlight the importance of considering the
Breit interaction for alkaline Earth metal atoms.
