Quantum and classical studies of the O( ³P) + H ₂(v=0-3,j=0) → OH+H reaction using benchmark potential surfaces

The excitation function for O( ³P)+H ₂(v=0-3,j=0)→OH+H from threshold to 30 kcal/mol collision energy was studied. It was observed that the rotational distributions tend to cluster around high rotational quantum numbers. The differences were found to arise because of vibrational adiabaticity in the quantum dynamics. The results show that the reactive threshold drops from 10 kcal/mol for v=0 to 6 for v=1, 5 for v=2 and 4 for v=3, which suggest a slower increase in rate constant with vibrational excitation above v=1 than below.