To confirm that the structure of the landscape is determined largely by the hydrogen bond interactions, the local minima within each funnel were classified by their hydrogen bond motifs (Fig. ). Indeed, all structures connected to α or β by barriers lower than 25 kJ mol -1 maintain the same hydrogen bonding as the starting structure, i.e. dimers within the α funnel and chains within the β funnel. At thresholds 30 and 35 kJ mol -1 above α, we start to see changes in hydrogen bond motifs: two structures with hydrogen bond chains within the α funnel and several crystal structures within both funnels that are not classified as either chains or dimers. Finally, at 40 kJ mol -1 above α, the two funnels are connected.