FIGURE 1. Bridging angles and girths in zeolites and IMs.
From the following article:
Colossal cages in zeolitic imidazolate frameworks as selective carbon dioxide reservoirs
Bo Wang, Adrien P. Côté, Hiroyasu Furukawa, Michael O'Keeffe & Omar M. Yaghi
Nature 453, 207-211(8 May 2008)
doi:10.1038/nature06900
a, Si2O in zeolites. b, Zn2(2-methylimidazolate), mIM, in ZIF-8 (structure symbol sod). c, Zn2(benzimidazolate), bIM, in ZIF-11 (rho). d, Zn2(5-chlorobenzimidazolate), cbIM, in ZIF-95 and ZIF-100 (previously unknown topologies).