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-DH2X

Use the PM6-DH2X semiempirical model instead of the default model, PM7 [19]. It combines the PM6 model [18] with the DH2X model [23] for interatomic pairwise corrections for dispersion, hydrogen bonding, and halogen 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 DH2X model.

Warning

There are terms missing from the analytical gradients of the DH2X 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.