Figure 2.

Concept and application of atomistic modeling, where a material is simulated based on the motion of atoms and molecules. Panels (a) and (b) show the transition from the quantum mechanical treatment of an atom or molecule to a point of mass, and the use of interatomic and intermolecular force fields to describe their interactions in classical molecular dynamics. The image in panel (c) shows a large-scale model of a tropocollagen molecule in explicit solvent, representing a three-dimensional model of the most abundant structural protein (courtesy A. Gautieri).