| nNuclei | Number of nuclei to calculate hyperfine structure for. |
| Jmin | Minimum J to use in calculation - set to -1 (default) to use value from the species. |
| Jmax | Maximum J to use in calculation - set to -1 (default) to use value from the species. |
| Colour | Colour - set to "None" to take value from elsewhere. |
| PointGroup | Point group - C1, Ci, C2, Cs, D2, C2v, C2h or D2h |
| Representation | Representation - Ir, IIr, IIIr, Il, IIl or IIIl |
| SReduction | Use Watson's S reduction (as opposed to A). |
| eeWt | Statistical weight for ee levels |
| eoWt | Statistical weight for eo levels |
| oeWt | Statistical weight for oe levels |
| ooWt | Statistical weight for oo levels |
| C2zAxis | a, b, or c; C2 axis in C2v; out of plane axis in Cs |
| C2xAxis | a, b, or c; out of plane axis in C2v |
| PseudoC2v | Ignore any operators breaking C2v symmetry. |
| FakeSym | Turn off transition moment test. |