An analytical foundation for statistically identifying key crystallographic descriptors for zeolite frameworks is presented in this paper. A new set of descriptor formulations containing various aspects of information about zeolite crystal structure is introduced. Selected crystallographic structure data for all known zeolite structure types were analyzed using principal components (PC) and partial least squares in order to understand the statistical distribution and hence help design new zeolites. Critical crystallographic ratios and transformed variables with good correlations to average ring size were calculated. The principal components of the framework descriptors were used to identify the important linear combinations of critical descriptors and to identify statistical outliers. Partial least squares was used to predict the average ring size based on these descriptors. These new secondary descriptors were tested against experimental findings of zeolite analogue structures demonstrating the value of these secondary descriptors as a guide for future combinatorial experiments. (C) 2003 Elsevier Science B.V All rights reserved.