The number of possible isomers increases exponentially as the number of linker fragments comprising the pore grows. For example, the UiO-6x structure (fcu fcu fcu net) contains eight tetrahedral (𝑇 𝑟𝑖 4 𝐷𝑖 6 ) and four octahedral (𝑇 𝑒𝑡 6 𝐷𝑖 12 ) pores per unit cell. A mono-functionalized 𝑇 𝑟𝑖 4 𝐷𝑖 6 pore has 172 distinct isomers, while a similarly mono-functionalized octahedral, 𝑇 𝑒𝑡 6 𝐷𝑖 12 , pore has 354024 distinct isomers, leading to a truly staggering number of distinct structures. Yet, the chemical environment 'seen' by a guest adsorbate molecule in the pore of such a cage structure may be relatively simpler, as any given molecule is likely to only interact with a limited number of functional groups. We therefore characterise each pore environment by the pair distances between functional groups and the frequency of these distances over all possible pore isomers.