Vacuum, implicit, or explicit solvent environments. Ground state only. The great computational speed of molecular mechanics allows for its use in procedures such as molecular dynamics, conformational energy searching, and docking, that require large numbers of energy evaluations. Interactions are based on springs and classical potentials. Interactions must be preassigned to specific sets of atoms.
Interactions determine the spatial distribution of atom-like particles and their energies .
Note how these principles differ from those of quantum mechanics . The mechanical molecular model considers atoms as spheres and bonds as springs. These properties are easiest to describe mathematically when atoms are considered as spheres of characteristic radii. The object of molecular mechanics is to predict the energy associated with a given conformation of a molecule. However, molecular mechanics energies have no meaning as absolute quantities.