Three benchmark systems representing small-, medium-, and large-sized reactions were curated to benchmark the accuracy and cost of four sampling schemes for using the model reaction TS as a starting point for a TS search of a larger parent reaction (Fig. ). Five reactions of γketohydroperoxide (R1 in Fig. ) and L-glucose (R2) as reactants were selected for the small-and medium-sized reaction systems, respectively, covering both b2f2 and b3f3 elementary reactions and various reaction mechanisms such as korcek cyclization, keto-enol tautomerization, water elimination, isomerization, etc. The number of heavy atoms in these two systems are 6 and 12, respectively, and the reference TS structures are obtained from our recent reaction exploration study. The large-sized reaction benchmark comprises three systems that were originally discussed in our reaction conformational sampling study: Table :