Three distinct types of reactions were discovered during the network exploration that are distinguished by their reactions with the adsorbed carbon species. All instances of each class exhibit ∆G † < 70 kcal/mol. The first types is responsible for lengthening (or breaking as the reverse reaction) the carbon backbone (Type I in Fig. ). The TS of the Type I reaction involves a "C=C" moiety bonding to the catalyst to form a four-coordinate Ga intermediate that precedes bond formation with an adsorbed alkyl species. The second type of reaction is β-hydride transfer that enables liberation of an oligomer and closes an oligomerization cycle (Type II in Fig. ). In the TS, the β-hydrogen of the adsorbed alkyl species transfers to an incoming olefin, which binds to the Ga center and becomes a new adsorbate. An oligomerization cycle can also be completed by a βhydride elimination step to form Ga-hydride, but YARP predicts a much higher activation energy for this pathway. The third type of reaction produces an alkane, leaving a hydrogen-deficient adsorbed species, like Ga-vinyl (Type III in Fig. ). The TS of the Type III reaction resembles that of Type II, except that the hydrogen transfers to the α-carbon. Alkane formation has been reported in multiple olefin oligomerization experiments, which may be explained by moderate-barrier Type III pathways. Further, we hypothesize that the products of type III reactions may undergo additional type I and type II steps. The combination of type I-III reactions may eventually liberate alkynes and aromatics that are commonly considered coke precursors. In addition to recapitulating the expected Cossee-Arlman oligomerization cycle, these elementary reaction types can also participate in several catalytic cycles for olefin isomerization and chain cracking (Fig. ). Interestingly, following the formation of 1-butene and the recovery of the Gaethyl intermediate (species 5 in Fig. ), where a Cossee-Arlman oligomerization cycle is about to finish, the 1-butene molecule can be re-adsorbed with a simple rotation and react with Ga-ethyl again through another β-hydride transfer step (type II), producing Ga-2-butyl (species 6 ). This newly reported intermediate can undergo a facile type II reaction, forming cis-or trans-2-butene (only cis-2-butene formation is considered here, species 14 ). Alternatively, Ga-2-butyl can undergo additional type I and II reactions to form Ga-methyl with physisorbed propylene (species 8 ). Intriguingly, there can be another re-adsorption step of propylene on Ga-methyl, resulting in a Ga-isobutyl species (species 15 ), which eventually leads to isobutene (species 17 ). Throughout the isomerization and cracking pathways, the type III step can occur on each Ga-alkyl species.