NCI Mode

For systems with non-covalently interacting molecules, crest provides a special runtype invoked with the –nci flag:

crest struc.xyz --nci

This will apply a wall potential to prevent the dissociation of molecules during MTD and MD simulations.

Warning: Especially for systems containing non-bonded molecules, conformer generation can be complex, and the results of a single crest run are likely insufficient to find the optimal conformer.

For systems with multiple molecules, it is highly recommended to run crest multiple times on the same system and combine the results. You can also sort the combined ensemble using crest, as explained in the additional features chapter. Additionally, it may be helpful to try different settings, such as adjusting the temperature of the MD runs (--tnmd <INT>) or increasing the number of search cycles (--mrest <INT>).

Adjusting the wall potential to your needs can also become very relevant. This can be done with the --wscal <REAL> flag, where <REAL> is a scaling of the wall potential size (per default 1.0). To see the influence of the wall potential, the --keepdir flag can be used to allow checking the trajectories.

Note: To generate reasonable starting structures, the xtb docking can be used.

Further options for tuning the sampling behavior can be found in the documentation.