Possible intramolecular bound interaction types are:
| Value | Description |
|---|---|
| angle | A normal angle interaction between three bound atoms |
| bond | A normal bond interaction between two bound atoms |
| improper | An improper torsion between four (not necessarily bound) atoms |
| torsion | A proper torsion interaction between four bound atoms |
| ub | A Urey-Bradley 1,3 term between two atoms at the extreme of a related angle |