Figure shows the major products from phenomenological rate coefficients. Under practically all conditions studied, αR + O 2 proceeds via a well-skipping reaction to form HO 2 and isobutanal. Even the stabilized αRO 2 formed at low temperature and high pressure forms the same product or the hydrogen-bonded adduct, as shown in Figure . This result is consistent with isobutanol oxidation experiments between 500-700 K, which show isobutanal as a major product. The main products, HO 2 and isobutanal, could also form by direct hydrogen abstraction of αR by O 2 , which was not studied in this work. However, based on the work of an analo-gous ethanol network by Zádor et al., this channel is unlikely to be important even at temperatures as high as 1000 K. Because the dominant channel from αR + O 2 makes HO 2 , and not a carbon-centered radical, αR does not lead to significant low-T chain-branching via second O 2 addition. (The HO 2 can lead to chain branching via H 2 O 2 , but typically that only becomes important above 750 K). Since the αR is predicted to be the dominant radical from isobutanol combustion, a large negative temperature coefficient effect is not expected. This is in agreement which agrees with previous experiments that found no negative temperature coefficient region in isobutanol combustion. 5,8 is often the major sink of βRO 2 radicals. The microcanonical rates of the major intermediates are shown in Figure . Of all the pathways available to βRO 2 , three pathways dominate at different energies. At the lowest energies (< -65 kJ/mol, i.e. below the zero-point energy of βQOOH[O] ), β-αQOOHIsom, which occurs through tunneling, is the fastest reaction. After forming βQOOHα at this low energy, it will likely form trisub_epoxy + OH through βEpoxyFromα, as shown in Figure .