CREST is an utility/driver program for the xtb program. Originally it was designed as conformer sampling program, hence the abbreviation Conformer-Rotamer Ensemble Sampling Tool, but now offers also some utility functions for calculations with the GFNn-xTB methods. Generally the program functions as an IO based OMP scheduler (i.e., calculations are performed by the xtb program) and tool for the creation and analysation of structure ensembles. The key procedure implemented in CREST is a conformational search workflow abbreviated as iMTD-GC. The iMTD-GC workflow generates conformer/rotamer ensembles (CREs) by extensive metadynamic sampling (MTD) based on, with an additional genetic z-matrix crossing (GC) step at the end. Other standalone functionalities that are included in CREST are parallel optimization and screening functions for GFNn–xTB, the function to sort (e.g. for NMR equivalencies) externally created ensembles, and some automated procedures for the protonation, deprotonation and tautomerization of structures. The main publication for the CREST program can be found at Phys. Chem. Chem. Phys., 2020, 22, 7169-7192.
|crest||Conformer-Rotamer Ensemble Sampling Tool based on the GFN methods|