Table 4 Atom and bond primitives for encoding of ‘augmented atoms’ in SMARTS
Feature | SMARTS encoding | Special case |
|---|---|---|
Atom primitives | ||
 Element | # <atomic number> |  |
Bond primitives | ||
 Single bond | – | @ (!@) for ‘in ring’ (‘not in ring’) |
 Double bond | = | @ (!@) for ‘in ring’ (‘not in ring’) |
 Triple bond | # | @ (!@) for ‘in ring’ (‘not in ring’) |
 Aromatic bond | : |  |