Fig. 6
From: Revealing and exploiting hierarchical material structure through complex atomic networks
The structure of the metal-organic framework MOF-5 (Zn4O(BDC)3, where BDC2– is 1,4-benzenedicarboxylate) and its modular decompositions. This structure has 106 atoms per unit cell. The two lowest minima have very similar values for the normalised information, with I = 0.163 at w s = 2 and \(d_{{\rm{eff}}}^{\rm{*}} = 3\) and I = 0.166 at w s = 1 and \(d_{{\rm{eff}}}^{\rm{*}} = 2\). Unlike d *, which is a physical distance threshold, the distance threshold parameter \(d_{{\rm{eff}}}^{\rm{*}}\) is dimensionless and expressed as the multiple of the summed atomic radii for a given pair of atoms (see text). Both decompositions consist of two modules, one of which appears six times and has D2h symmetry, and the other one of which appears twice and has T d symmetry. The modules for I = 0.163 are one with 16 atoms (8 C, 4 O, 4 H) and one with five atoms (4 Zn, 1 O)
