Four-component relativistic density functional calculations of heavy diatomic molecules

We perform accurate four-component calculations for heavy closed-shell diatomic molecules in the framework of relativistic density functional theory using local and gradient corrected density functional schemes. As examples we have chosen Cu2, Ag2, Au2, Tl2, Pb2, Bi2, and Pt2. The potential energy curves show the quality, and the discrepancies of the density functionals unscreened from any approximation of the relativistic effects.