A side view of the three-fold 2D→2D parallel interpenetrating
sql sheets (view down the a axis). (bottom) A drawing showing the parallel polycatenation of 3-fold thick layers to give a 3D entanglement. From the figure it is evident that the removal of 3 layers will disconnect the entanglement (Index of Separation Is = 3).
Source: Ligand isomerism-controlled structural diversity of cadmium(II) perchlorate coordination polymers containing dipyridyladipoamide ligands
Yi-Fen Hsu, Hui-Ling Hu, Chia-Jun Wu, Chun-Wei Yeh, Davide M. Proserpio and Jhy-Der Chen
CrystEngComm, 2009, 11, 168-176.
The modern nomenclature for nets adopts the 3-letter code (as "dia","ths", "pcu","pts" in bold font) proposed by Mike O'Keeffe as code-name for nets (similar to zeolites names), in order to identify uniquely topologies and avoid/minimize errors. See http://rcsr.anu.edu.au/definitions/symbol, The Reticular Chemistry Structure Resource (RCSR) Database of, and Symbols for, Crystal Nets, O'Keeffe, M.; Peskov, M/ A.; Ramsden, S. J.; Yaghi, O. M. Accts. Chem. Res. 2008, 41, 1782-1789. and Vertex-, face-, point-, Schlafli-, and Delaney-symbols in nets, polyhedra and tilings: recommended terminology, V. A. Blatov, M. O'Keeffe and D. M. Proserpio CrystEngComm, 2009, DOI: 10.1039/B910671E
