Table 1.
Features
| Feature | Description | Size |
|---|---|---|
| Atom | 21 | |
| Atom type | H, C, O, N, or others | 5 |
| NumHs | Total number of H atoms attached to it | 1 |
| Degree | Its degree of unsaturation | 1 |
| Charge | Its formal charge | 1 |
| Valence | Its total valence | 1 |
| Ring | Whether it is included in a ring | 1 |
| Aromaticity | Whether it is included in an aromatic structure | 1 |
| Chirality | R, S, or others | 3 |
| Hybridization | s, sp, sp2, sp3, sp3d, sp3d2, or others | 7 |
| SMILES original symbol | 21 | |
| ( | Branch start | 1 |
| ) | Branch end | 1 |
| [ | Atom or atom group start | 1 |
| ] | Atom or atom group end | 1 |
| . | Ionic bond | 1 |
| : | Aromatic bond | 1 |
| = | Double bond | 1 |
| # | Triple bond | 1 |
| \ | cis | 1 |
| / | trans | 1 |
| @ | Chirality (above or below) | 1 |
| + | Cation (positive ion) | 1 |
| - | Anion (negative ion) | 1 |
| Ion charge | Numbers show ionic charge (2-7) | 6 |
| Start | Numbers show ring start | 1 |
| End | Numbers show ring end | 1 |