The disconnectivity graphs from the threshold simulations at both 2.5 (Fig. ) and 5.0 kJ mol -1 (Fig. ) indicate a high degree of connectivity between the sampled benzene structures. Even restricting to connections below 2.5 kJ mol -1 only eight distinct basins are observed, and increasing the energy threshold to 5.0 kJ mol -1 yields the entire low energy region as a single basin. The energy minimum of this basin being the ambient pressure form I structure. Notably, the high-pressure form III structure is indicated to not be stable at the ambient pressure of the calculations and transitions to form I as expected. Therefore, clustering the landscape into the basin minima yields a reduced landscape consisting of only the form I polymorph.