Here, I (E mn ) and I 0 (E mn ) are the densities of states for the transition state and reactant molecule, respectively. Application of this method to formaldehyde by Miller noted rates on the order of 10 6 s -1 . As well, they noted the importance of tunnelling effects only below the nanosecond scale, otherwise their contributions are minimal. Zhang and co-workers used this method to calculate ring deformation in 2-aminopyridine, with a rate constant of 8.69 × 10 11 s -1 . Interestingly, neither hydrogen transport or ring opening could compete with ring deformation, however the authors noted applicability issues.