Types of structure searches: Exact search

Exact search retrieves substances which match the query exactly
- All positions in the structure are blocked for further substitution
- All query rings are isolated
- No variable nodes are allowed in the query
- Variable bond values are allowed in the query
- Retrieves all substances having the same “connection table”
  - Unsubstituted substance
  - Stereoisomers
  - Isotopically labelled substances
  - Radicals
  - Ions
  - Homopolymers
Exact search may be used to find corresponding records in other structure searchable files (e.g. CASREACT)
Exact search will add hydrogens to all vacant positions
Exact search will not permit any other non-hydrogen atoms to be present