GROMACS
A molecular simulation toolkit for classical dynamics, with tools for system preparation, trajectories, analysis and free-energy workflows.
Where it fits
Biomolecular and condensed-phase simulations with established force fields.
Limits and practical considerations
Force-field quality and adequate sampling control scientific validity; ordinary classical models do not describe electronic rearrangement.
Licensing and access
Open source under LGPL-2.1; independently check force-field and auxiliary-tool terms.