Examples with OpenMM_PeriodicTorsionForce_addTorsion simtk.openmm.OpenMMLibrary.OpenMM_PeriodicTorsionForce_addTorsion used on opensource projects

Example 1 with OpenMM_PeriodicTorsionForce_addTorsion

use of simtk.openmm.OpenMMLibrary.OpenMM_PeriodicTorsionForce_addTorsion in project ffx by mjschnie.

the class ForceFieldEnergyOpenMM method addTorsionForce.

private void addTorsionForce() {
    Torsion[] torsions = super.getTorsions();
    if (torsions == null || torsions.length < 1) {
        return;
    }
    int nTorsions = torsions.length;
    amoebaTorsionForce = OpenMM_PeriodicTorsionForce_create();
    for (int i = 0; i < nTorsions; i++) {
        Torsion torsion = torsions[i];
        int a1 = torsion.getAtom(0).getXyzIndex() - 1;
        int a2 = torsion.getAtom(1).getXyzIndex() - 1;
        int a3 = torsion.getAtom(2).getXyzIndex() - 1;
        int a4 = torsion.getAtom(3).getXyzIndex() - 1;
        TorsionType torsionType = torsion.torsionType;
        int nTerms = torsionType.phase.length;
        for (int j = 0; j < nTerms; j++) {
            OpenMM_PeriodicTorsionForce_addTorsion(amoebaTorsionForce, a1, a2, a3, a4, j + 1, torsionType.phase[j] * OpenMM_RadiansPerDegree, OpenMM_KJPerKcal * torsion.units * torsionType.amplitude[j]);
        }
    }
    OpenMM_System_addForce(system, amoebaTorsionForce);
    logger.log(Level.INFO, " Added Torsions ({0})", nTorsions);
}