Other, more classical design patterns have also been leveraged to identify materials with anomalous mechanical behavior, and studied in order to match their macroscopic properties with a microscopic mechanism. For example, Erkartal studied the 3D covalent organic framework NPN-3 18 , where they identified "giant" negative linear compressibility and a breathing structural transition, linked to the diamondoid (dia) topology of the framework. Colmenero studied the NLC in two small-pore MOF structures, (ZnC 4 O 4 • 4H 2 O) and (Ti 2 (C 2 O 4 )O 3 • 2H 2 O), and the impact of hydration on the mechanics of the framework: they identified what they 16 PPF = Pillared Porphyrin Framework. 17 ZIF = Zeolitic Imidazolate Framework; gis is a topological code from the Reticular Chemistry Structure Resource (RCSR) database corresponding to the gismondine zeolite. 18 NPN = Nitroso Polymer Network; NPN-3 was first reported in Ref. .