Chemical information systems are structure-based
- Chemical information systems are characterized by an information model
which is based on associating data with molecular structure.
- Sometimes the structure-data connection is overt,
e.g., data in Thor databases are explicitly indexed by structure.
- Usually the connection between structure and data is indirect,
e.g., in CAS and MDL systems, structural information is indexed by a
registration number and stored much like any other data.
- In either case, the structure provides an important index for