CoMPullingForce #

It applies a force to the center of mass of the specified particles.

Example #

[[forcefields.external]]
interaction = "CoMPullingForce"
parameters  = [
    {indices = [0, 1, 2], force = [0.0, 0.0, 0.0144]},
    {indices = "[0, 10)", force = 0.0144, direction = [1.0, 1.0, 1.0]},
    {indices = ["[0, 99]", "[200, 300)"], force = 0.0144, direction = [1.0, 1.0, 1.0]},
    # ...
]

Input Reference #

• interaction: String
  • Name of the interaciton. Here, it is "CoMPullingForce".
• parameters: Table
  • indices: Array of Integers, String, or Array of Strings
    • The indices of the particles.
    • If it is an Array of Integers, then the integers will be the indices of the particles.
    • If it is a String, the string will be interpreted as an interval of the indices by a standard form. A string "[0, 10)" means integers from 0 to 9 (half-open interval).
    • If it is an Array of Strings, then the intervals will be concatenated.
    • Note that the indices will be made unique.
  • force: Array of Floatings (length = 3) or Floating
    • If it is an Array of Floatings, it represents the force to apply.
    • If it is Floating, it represents the strength of the force. In that case direction must be provided.
    • The unit depends on the unit system you choose in [units] (e.g. kcal/mol/Å).
      • 1 kcal/mol/Å ~ 69.5 pN.
  • direction: Array of Floatings
    • The cartesian coordinate (x, y, and z in this order) of the force direction. It will be normalized.