Within the elastic band method, the top level construct, a string defining a path between two sites in free energy space, is decomposed into a set of individual nodes which perform short umbrella sampling calculations using a set of parallel molecular dynamics and Monte Carlo calculations. At the end of a data-gathering run, the position of the node in free-energy space is updated, and through communication with neighboring elements, the path is redefined.
The figure at right presents a simple validation of the metadynamics and elastic band method codes in SSAGES suite. The heat-map is generated using metadynamics performed on a single particle within a two dimensional field containing three Gaussian potentials, one peak and two wells. The minimum free-energy pathway between the wells is obtained through evolution of a string with 96 nodes. The system in this case evolves until only minimal driving forces from the underlying FES remain; extended simulation would push the elastic band out to hug the bounding surface.