External Electric Field

NAMD provides the ability to apply a constant electric field to the molecular system being simulated. Energy due to the external field will be reported in the MISC column and may be discontinuous in simulations using periodic boundary conditions if, for example, a charged hydrogen group moves outside of the central cell. There are two parameters that control this feature.

• eFieldOn $<$ apply electric field? $>$
  Acceptable Values: yes or no
  Default Value: no
  Description: Specifies whether or not an electric field is applied.

• eField $<$ electric field vector $>$
  Acceptable Values: vector of decimals (x y z)
  Description: Vector which describes the electric field to be applied. Units are ${\rm kcal} / ({\rm mol \; \AA} \; e)$, which is natural for simulations. This parameter may be changed between run commands, allowing a square wave or other approximate wave form to be applied.