Electric dipole polarizability from perturbed Relativistic   Coupled-Cluster Theory: application to Neon
  We develop a method based on the relativistic coupled-cluster theory to incorporate a perturbative interaction to the no-pair Dirac-Coulomb atomic Hamiltonian. The method is general and suitable to incorporate any perturbation Hamiltonian in a many electron atom or ion. Using this perturbed relativistic coupled-cluster (PRCC) theory we calculate the electric dipole polarizability, $\alpha$, of Neon. The linearized PRCC results are in very good agreement with the experimental value. However, the results of the nonlinear PRCC shows larger uncertainty but it is consistent with the observations from earlier works. 
S. Chattopadhyay, B. K. Mani and D. Angom
physics.atom-ph