The default weighting values used for reference data are shown in Table 1. These defaults can be modified by keywords. RELH=n.n will multiply the default heat of formation weight by n.n. If n.n is larger than 1.0, that will increase the importance of heats of formation. RELG=n.n will modify geometries, RELH=n.n: dipole moments, and RELI=n.n: ionization potentials. That is, these keywords modify the relative weights of the various reference data
At least one of these keywords, preferably RELH=n.n, should not be used in an optimization.
If a molecule already has a modified weight, then the default weight will be multiplied by that weight as well as by the relative weight.
| Table 1 | ||||
| Parameter | Default value | Unit | ||
| ΔHf | 1.0 | Mol.kcal-1 | ||
| Dipole | 10.0 | Debye-1 | ||
| I.P. | 5.0 | eV-1 | ||
| Geometry | 0.4 | mol.Angstrom.kcal-1 |