Interaction function and force fields¶

To accommodate the potential functions used in some popular force fields (see Interaction function and force fields), GROMACS offers a choice of functions, both for non-bonded interaction and for dihedral interactions. They are described in the appropriate subsections.

The potential functions can be subdivided into three parts

  1. Non-bonded: Lennard-Jones or Buckingham, and Coulomb or modified Coulomb. The non-bonded interactions are computed on the basis of a neighbor list (a list of non-bonded atoms within a certain radius), in which exclusions are already removed.

  2. Bonded: covalent bond-stretching, angle-bending, improper dihedrals, and proper dihedrals. These are computed on the basis of fixed lists.

  3. Restraints: position restraints, angle restraints, distance restraints, orientation restraints and dihedral restraints, all based on fixed lists.

  4. Applied Forces: externally applied forces, see chapter Special Topics.