Relativistic Effects From Coupled-Cluster Theory

In this chapter we first discuss the theory and computational challenges of the relativistic coupled-cluster methods. Example calculations of heavy-atom-containing molecules are then presented to demonstrate the importance of scalar-relativistic, spin-orbit coupling, and electron-correlation effects on molecular properties as well as the applicability and usefulness of relativistic coupled-cluster methods in calculations aiming at high-accuracy results. A unique applicability of the spinor-based relativistic coupled-cluster methods is also highlighted using the calculations of open-shell actinide-containing small molecules. Finally, a summary is given together with an outlook into future developments.