The douglas-kroll-hess approach to relativistic density functional theory: Methodological aspects and applications to metal complexes and clusters

Basic theoretical aspects of relativistic density functional theory as well as methodological details and key applications of the relativistic variant of the linear combination of Gaussian-type orbitals density functional (RLCGTO-DF) method are presented. Starting from the quantum electrodynamical Hamiltonian, an overview over relativistic density functional theory is given. The adaption of the second-order Douglas-Kroll-Hess scheme for solving the Dirac-Kohn-Sham equations results in a computationally efficient and numerically stable two-component Kohn-Sham formalism which is well suited for molecular applications, in particular due to the availability of analytical energy gradients. Finally, various applications of the RLCGTO-DF method to metal clusters to metal-ligand interactions, and to metal complex reactions are reviewed.