Add plane harmonic restraint#

Restraining atoms to lie on a 2D plane with harmonic potential wells in OpenMM.

The function molsysmt.third_party.openmm.forces.add_plane_harmonic_restraint() tethers selected atoms to a defined planar geometry.

Added in version 1.0.0.

API documentation

Follow this link for a detailed description of the input arguments, raised errors, and returned objects: molsysmt.third_party.openmm.forces.add_plane_harmonic_restraint().

Basic usage#

Let’s add a planar harmonic restraint:

import molsysmt as msm

molsys = msm.convert(msm.systems['Trp-Cage']['1l2y.h5msm'], to_form='molsysmt.MolSys')
force = msm.third_party.openmm.forces.add_plane_harmonic_restraint(molsys, point='[0,0,0] nm', normal_vector=(0,0,1), selection=[0], force_constant='500 kJ/(mol*nm**2)', return_force=True)
print('Plane harmonic restraint created:', type(force))

[0. 0. 0.] nm
Plane harmonic restraint created: <class 'openmm.openmm.CustomExternalForce'>