This study focuses on an attempt to determine the internal pore architecture for two unknown zeolites through comparison with a selection of known zeolites. Unlike most studies, we also attempt to gain insight into structures by analyzing synthesis conditions. The details of structure-directing agents (SDAs) for zeolite formation and the inorganic context in which they do and do not work provide important data. In addition to synthesis comparisons, we show comparative adsorption data (2,2-dimethyl butane) and catalysis selectivity (methanol conversion and hexane cracking) for the unknown and selected known zeolites that should have relevant pore features. We focused on zeolites with large and intermediate pores, particularly with channel intersections, and those with portals opening into larger cavities. In these three analytical approaches, the unknowns IM-5 and SSZ-57 matched best as multidimensional 10-ring zeolites. (c) 2007 Elsevier Inc. All rights reserved.