RECP CALCULATIONS FOR REACTIONS OF H-2 WITH PT, OS, IR, AND RE - A SYSTEMATIC COMPARISON

Relativistic effective core potential calculations have been carried o ut for the reactions of Pt, Os, Ir, and Re with H-2. The calculations demonstrate the importance of a singly occupied 6s orbital for forming a strong bond. Pt and Ir have low-lying states with such occupancy, w hereas Os and Re only attains this through a rather costly excitation. In consequence, the reaction barriers are considerably smaller for Pt and Ir than for Os and Re.