Li, XiDeem, Michael W.2014-07-182014-07-182014Li, Xi and Deem, Michael W.. "Why Zeolites Have So Few 7-Membered Rings." <i>The Journal of Physical Chemistry C,</i> (2014) American Chemical Society: http://dx.doi.org/10.1021/jp504143r.https://hdl.handle.net/1911/76250Known zeolite structures have relatively few 7-membered rings. Previous quantum mechanical calculations suggest there is no particular energy penalty for 7-membered rings. Predicted zeolite structures sampled from all possible symmetries also do not explain why there are so few observed 7-membered rings. Here, we analyze the ring size distributions of predicted structures as a function of energy and density. We show that predicted structures with low density, in the range where known zeolites exist, have relatively few 7-membered rings. It appears that the constraint of proximity to the low-density edge of predicted structures is what leads to a low probability of 7-membered rings. These results suggest that low-density predicted structures are similar to known zeolites and of greatest interest as new synthetic targets.engThis is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by the American Chemical Society.Journal articlezeolites7-ringshttp://dx.doi.org/10.1021/jp504143r