bool OESetTorsion(OEHierResidue &res, unsigned torType, double radians)
bool OESetTorsion(OEChem::OEAtomBase *atom, unsigned torType, double radians,
                  unsigned assume=OEAssumption::Default)

Sets one of the standard torsions in a residue to a particular value in radians. The specific torsion is indicated by passing one of the constants from the OEProtTorType namespace into the torType parameter. The residue is specified by its OEHierResidue class or by any OEAtomBase from the residue.