Application of relativistic coupled cluster theory to elastic scattering of electrons from confined Ca atoms

We have developed relativistic coupled-cluster (RCC) theory to study elastic scattering of electrons from free and confined Ca atoms. For this purpose, we first investigated electron correlation effects on the atomic properties of the Ca atom trapped inside an attractive spherically symmetric potential well of an endohedral fullerene C60 cluster and obtained electron correlation energy, ionization potential and dipole polarizability of this atom. Our results are compared with the reported calculations employing multi-configuration Hartree-Fock (MCHF) method. We found that trends in correlation energy with respect to the potential depth are the same, but magnitudes are very large in the relativistic calculations. Finally, using the obtained charge density and phase shift analysis technique we determined the differential and total cross-sections for elastic scattering of electrons from free and confined Ca atoms and demonstrated the role of potential depth in these properties.