O. Gropen et al., RECP CALCULATIONS FOR REACTIONS OF H-2 WITH PT, OS, IR, AND RE - A SYSTEMATIC COMPARISON, Theoretica Chimica Acta, 87(4-5), 1994, pp. 373-385
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.