An atomic structure can reveal a lot about how a biomolecule works. Atoms in a biomolecule are constantly moving affecting molecular function and intermolecular interactions. One would like to examine these biomolecules in action, to disrupt them at the atomic level and see how they respond. It's tough to control the mobility of individual atoms. A computer simulation of the relevant biomolecules is an action of choice. Molecular dynamics (MD) simulations describe the movement of each atom in a protein or other molecular system over time using a broad model of the physics regulating interatomic interactions. In recent years, MD simulations have become increasingly important in molecular biology and drug development.