Quantum reactive scattering studies of the CN + H2 → HCN + H reaction: the role of the non-reactive CN bond

An extended version of the rotating-bond approximation (RBA) has been developed to study the title reaction, in which CN stretching is added to usual CH stretching and bend degrees of freedom in a coupled channel expansion. Calculations have been done on potential energy surfaces developed by Sun and Bowman (SB) and by ter Horst, Schatz, and Harding (TSH). The HCN vibrational product state distribution calculated on TSH surface shows significant population in both CH and CN stretching, indicating that the CN bond is not a spectator.