A new relativistic scheme in Dirac–Kohn–Sham theory

The relativistic scheme by the elimination of small components (RESC) of the four-component Dirac equation proposed previously has been incorporated into density functional theory (DFT). RESC–DFT results in a computationally efficient and numerically stable two-component Kohn–Sham formalism, suited for molecular applications. Illustrative calculations for AgH, AuH, AgCl, and AuCl have been performed employing various exchange-correlation functionals. A good agreement with experiment is obtained.