Beyond the use of the table of contents file, as described above, we also used an auxiliary database of general ring fragments to improve database hit rate. As indicated in Table , we tried using the generic fragments before and after placing fragments. Using the generic rings results in better RMSD, in exchange for somewhat longer prediction time (e.g., 20.6 s vs. 54.8 s). More importantly, the generic fragments reduce bond and angle errors and increase stereochemical success. By searching ring fragments before rigid fragments, the prediction accuracy slightly improved but speed and success rate deteriorated. The final implementation places generic ring fragments after exact matching with rigid fragments.