Even "rigid" MOFs possess some degree of flexibility where the organic linker can rotate about the linker axis. Consequently, the distances for every pair can deviate from the original, symmetric position. To consider the effect of such linker rotation, we rotate each linker through ±30 • , keeping the centre of rotation (i.e. the centre of the linker along the connector axis) fixed. For each FG-FG distance in the original descriptor, we record the minimum and maximum distance that can be attained by rotation of the linkers. Table lists the minima and maxima for each FG-FG distance in the 𝑇 𝑒𝑡 2 𝐷𝑖 4 , the 𝑇 𝑟𝑖 4 𝐷𝑖 6 (tetrahedral), 𝑇 𝑒𝑡 6 𝐷𝑖 12 (octahedral) pores are provided in the Supporting Information Section S4. The inclusion of linker rotation to the histogram on Figure assumes no rotation barrier, addition of a rotation barrier would restrict the tails of each peak.