Official Resources
- Homepage: https://www.ccdc.cam.ac.uk/
- Documentation: https://www.ccdc.cam.ac.uk/solutions/software/csd/
- License: Commercial (CSD requires license; Access Structures is free)
Overview
The Cambridge Crystallographic Data Centre (CCDC) maintains the Cambridge Structural Database (CSD), the world's largest curated repository of experimentally determined small-molecule organic and metal-organic crystal structures. Established in 1965 with historical structures dating back to the 1920s, the CSD contains over 1.4 million accurate 3D structures derived from X-ray, neutron, and electron diffraction analyses.
The CSD is a CoreTrustSeal certified data repository used by researchers across pharmaceutical, agrochemical, and fine chemicals industries. Each structure is curated to include bibliographic data, chemical connectivity, and validation results, with additional metadata such as common names, bioactivity, natural source, and cross-references to enantiomers, racemates, and polymorphs. The CCDC also maintains the Inorganic Crystal Structure Database (ICSD) in partnership with FIZ Karlsruhe. CCDC software enables scientists to search, visualize, and analyze structural data to extract insights for materials and drug discovery.
Scientific domain: Crystallography, structural chemistry, materials databases
Target user community: Crystallographers, pharmaceutical researchers, materials scientists
Theoretical Methods
- Crystal structure determination from diffraction data
- Structure validation and curation
- Substructure and similarity searching
- Conformational analysis
- Intermolecular interaction analysis
- Crystal structure prediction (via CSD knowledge)
- Hydrogen bond motif analysis
- Polymorph analysis
Capabilities (CRITICAL)
- Over 1.4 million curated crystal structures
- Free structure access via Access Structures (with DOI for each structure)
- WebCSD for online searching and visualization
- ConQuest for advanced searches (substructure, 3D, text)
- Mercury for structure visualization and analysis
- CSD-CrossMiner for scaffold-based searching
- CSD-Particle for intermolecular interaction analysis
- 14,992 polymorph families catalogued
- 182,103 melting points available
- Structure deposition service
- FAIR principles compliance (each structure has DOI)
Inputs & Outputs
Input formats:
- CIF (Crystallographic Information File) for structure deposition
- Structure search queries (text, substructure, unit cell, formula)
- Experimental diffraction data for deposition
Output data types:
- 3D crystal structures with atomic coordinates
- Crystallographic parameters (unit cell, space group)
- Curated metadata (bibliographic, chemical, validation)
- Interaction analysis results
- Substructure search results
- Polymorph and conformer information
Interfaces & Ecosystem
- Software suite: ConQuest (search), Mercury (visualization), CSD-Materials, CSD-Discovery
- Programming APIs: CSD Python API for programmatic access
- Web services: Access Structures, WebCSD
- Partnership: FIZ Karlsruhe for ICSD
- Data standards: CIF format, FAIR principles
- Integration: Materials Project, other databases via cross-references
Limitations & Known Constraints
- CSD requires commercial license for full access
- Focused on small molecules (organic and metal-organic)
- Inorganic structures in separate ICSD database
- Some advanced analysis tools require additional licenses
- Database coverage depends on published literature
Performance Characteristics
- WebCSD provides fast online access to all structures
- ConQuest handles complex substructure searches efficiently
- CSD Python API enables batch processing
- Database updates regularly with new structures
- 3D visualization with Mercury is interactive and responsive
Comparison with Other Codes
- vs ICSD: ICSD focuses on inorganic crystals; CSD focuses on organic/metal-organic
- vs Materials Project: MP has computed properties; CSD has experimental structures
- vs COD (Crystallography Open Database): COD is open and free; CSD is curated and commercial
- vs PDB (Protein Data Bank): PDB focuses on biological macromolecules; CSD on small molecules
Best Practices
- Use Access Structures for free retrieval of specific structures
- Use ConQuest for advanced substructure and motif searching
- Deposit structures upon publication for community access
- Leverage CSD knowledge for crystal structure prediction
- Use Mercury for publication-quality structure visualizations
- Use CSD Python API for automated analysis workflows
Verification & Sources
Primary sources:
- CCDC website: https://www.ccdc.cam.ac.uk/
- CSD page: https://www.ccdc.cam.ac.uk/solutions/software/csd/
- Access Structures: https://ccdc.cam.ac.uk/structures/
- WebCSD: https://www.ccdc.cam.ac.uk/solutions/software/webcsd/
Confidence: VERIFIED - Official CCDC website and services confirmed accessible