Force fields

The force fields used by NAMD are compatible with those used by the programs X-PLOR and CHARMm. It includes energy terms for electrostatics, van der Waals, linear bonds, angular bonds, dihedral bonds, improper bonds, and Hydrogen bonds. The potential energy function used by NAMD is

$$E_{\text{total}} = E_{\text{elec}} + E_{\text{vdw}} + E_{\tex... ...} + E_{\text{angle}} + E_{\text{d/i}} + E_{\text{constraint}}$$

The following subsections describe the individual energy terms in detail as well as how to determine the forces associated with each type of interaction.