Secondly, once the pairing of oxygen vertices has been established, the orientation of each ellagate ligand is considered. Each chelating ellagate ligand can have one of two orientations, related to one another by flipping the ligand to swap the positions of the two coordinating phenolic oxygen atoms of the catecholate. For clarity, the phenolic oxygen that is meta to the biaryl C-C bond is coloured blue in Fig. . The two orientations of EA are arbitrarily denoted a and b for each of the four ellagate linkers (see Supplementary Fig. -17 for details). Fig. shows that SU-105 and SU-106 have the same oxygen pairing, type 1, but are distinct from one another as the orientations of three of the four ellagate ligands are flipped, with SU-105 and SU-106 having the orientations aaba and abab respectively. On the other hand, SU-106 and SU-112 are built of the same Zr(EA)4 isomer, 1abab, however these MOFs are still regarded as distinct phases due to the aforementioned differences in framework interpenetration.