CRDGEN-385: Add 16 bicyclic ring templates by ZontaNicola · Pull Request #18 · rdkit/molecular_templates

ZontaNicola · 2026-03-18T14:59:38Z

This adds all sensible permutations of byciclic fused rings that are depicted as a regular polygon with an inner bridge
-outer rings of 5-8 atoms

Bridge sizes of 1-2 atoms
this provides alternative layouts for the same structure (e.g. 6 membered ring with a 1 atom bridge or 5 membered ring with a 2 atom bridge). Since we are now converting these to SMARTS, the appropriate one will be picked when substitutions are present. Here's an example

Templates are ordered so that shorter bridges come first (they look better)

PLEASE DO NOT MODIFY template_smiles.h DIRECTLY

Add your templates to the templates.smi file in this repository. Add one CXSMILES per line, and please do not insert any blank lines.
Commit your changes and create the PR. The CI workflow will run on the new templates and validate them, and once they are approved, they will be automatically added to the header.

For more information please check https://github.com/rdkit/molecular_templates/blob/main/README.md

- Added bicyclic templates with outer rings of 5-8 atoms - Bridge sizes of 1-2 atoms - Templates sorted by bridge size (1-atom first, then 2-atom) - Bond lengths ~1.42 matching existing templates - Properly oriented with bridgeheads horizontal and vertically flipped