Interestingly, we find the magnitude of correlation is not entirely correlated with the size of the ligand. The largest molecular subunit of DUT-60, which has an average radius of 12 Å at 40 K, shows a similar amount of contraction as NU-110, with an average radius 20 Å at 40 K. This suggests that the chemical constituents of the subunit strongly influences the amount of contraction. The ligand of DUT-60 and MOF-399 is comprised entirely of phenyl groups, whereas NU-110 contains additional alkyne groups to produce a larger ligand. It appears the alkyne functionality produces less contraction for a larger molecular unit.