Note

This website is presently under development. The primary website for MOPAC is still http://openmopac.net until the majority of its contents have been migrated here.

PM6-DH2

Use the PM6-DH2 semiempirical model instead of the default model, PM7 [19]. It combines the PM6 model [18] with the DH2 model [12] for interatomic pairwise corrections for dispersion and hydrogen bonding. See the Model Overview for a comparison of the various models available in MOPAC.

The DISP keyword can be used to print individual pairwise corrections from the DH2 model.

Warning

There are terms missing from the analytical gradients of the DH2 model. While these terms are often negligible, this issue can be avoided by using the NOANCI keyword to produce consistent numerical gradients, albeit at an increased computational cost.