Relativistic and electron-correlation effects in static dipole polarizabilities for main-group elements

In this study, I compute the static dipole polarizability of main-group elements using the finite-field method combined with relativistic coupled-cluster and configuration-interaction simulations. The computational results closely align with the values recommended in the 2018 Table of static dipole polarizabilities of neutral elements [Mol. Phys. 117, 1200 (2019)]. Additionally, I investigate the influence of relativistic effects and electron correlation on atomic dipole polarizabilities. Specifically, three types of relativistic effects impacting dipole polarizabilities are studied: scalar-relativistic, spin-orbit coupling, and fully relativistic Dirac-Coulomb effects. The results indicate that scalar-relativistic effects are predominant for atoms in groups 1 and 2, with minimal influence from spin-orbit coupling effects. Conversely, for elements in groups 13--18, scalar-relativistic effects are less significant, while spin-orbit coupling significantly affects elements starting from the fourth row in groups 13 and 14 and from the fifth row in groups 15--18. In each category of relativistic effects, the impact of electron correlation is evaluated. The results show that electron correlation significantly influences dipole polarizability calculations, particularly for atoms from groups 1, 2, 13, and 14, but is less significant for atoms from groups 15--18. This study provides a comprehensive and consistent data set of dipole polarizabilities and contributes to a systematic understanding of the roles of relativistic and electron-correlation effects in atomic dipole polarizabilities, serving as a valuable reference for future research.