The major pressure-dependent pathways in this work, shown in Figure , show general agreement with the conclu- sions drawn in Sun et al., though our calculations predict more alkene formation. Both studies predict that βR + O 2 gives stabilized βRO 2 at higher pressures and lower temperatures, with the switching of the major pathway at around 10 5 Pa and 1000 K. With lower pressures (T=1000 K), our calculations suggest alkene formation will dominate over the Waddington reaction, whereas those of Sun et al. suggest the reverse. Other major products in this work include ibutenol and trisub_epoxy, which Sun et al. also found as large secondary pathways. For the reactions of stabilized βRO 2 , this work and that of Sun et al. find the reaction forming βR + O 2 to dominate for all pressures at 800 K. For lower pressures (at 800 K), this work and that of Sun et al. predict the main secondary channel to be the Waddington pathway. However, at high pressures, Sun et al. found βQOOH[O] formation to be the main secondary channel, but this work finds it to be one of the slower pathways. This difference may have arisen from the approximations made to get phenomenological rates. If we use the modified strong collision method to obtain pressure-dependent rates from the master equation instead of the reservoir state method, we obtain more rapid formation of βQOOH[O], in better agreement with the results of Sun et al.