The importance of isotope-dependent transmission coefficients in calculating low-temperature isotope effects

We compare conclusions which may be drawn from our previous work (Truhlar et al. [5]), on the collinear H + H2 reaction concerning practical calculations of isotope effects with conclusions drawn by Wu et al. [1]. We present calculations designed to elucidate the differences in conclusions. We suggest that one should not assume that accurate isotope effects for reactions involving H and D can be calculated from transition state theory using transmission coefficients equal to unity, especially at room temperature and lower temperatures.