def test_angle_potential_handler(self):
top = OFFBioTop.from_molecules(Molecule.from_smiles("CCC"))
angle_handler = AngleHandler(version=0.3)
angle_parameter = AngleHandler.AngleType(
smirks="[*:1]~[*:2]~[*:3]",
k=2.5 * simtk_unit.kilocalorie_per_mole / simtk_unit.radian**2,
angle=100 * simtk_unit.degree,
id="b1000",
)
angle_handler.add_parameter(angle_parameter.to_dict())
forcefield = ForceField()
forcefield.register_parameter_handler(angle_handler)
angle_potentials = SMIRNOFFAngleHandler._from_toolkit(
parameter_handler=forcefield["Angles"],
topology=top,
)
top_key = TopologyKey(atom_indices=(0, 1, 2))
pot_key = angle_potentials.slot_map[top_key]
assert pot_key.associated_handler == "Angles"
pot = angle_potentials.potentials[pot_key]
kcal_mol_rad2 = unit.Unit("kilocalorie / (mole * radian ** 2)")
assert pot.parameters["k"].to(
kcal_mol_rad2).magnitude == pytest.approx(2.5)
def test_angle_potential_handler(self):
top = Topology.from_molecules(Molecule.from_smiles("CCC"))
angle_handler = AngleHandler(version=0.3)
angle_parameter = AngleHandler.AngleType(
smirks="[*:1]~[*:2]~[*:3]",
k=2.5 * omm_unit.kilocalorie_per_mole / omm_unit.radian**2,
angle=100 * omm_unit.degree,
id="b1000",
)
angle_handler.add_parameter(angle_parameter.to_dict())
from openff.system.stubs import ForceField
forcefield = ForceField()
forcefield.register_parameter_handler(angle_handler)
angle_potentials = forcefield["Angles"].create_potential(top)
top_key = TopologyKey(atom_indices=(0, 1, 2))
pot = angle_potentials.potentials[angle_potentials.slot_map[top_key]]
kcal_mol_rad2 = unit.Unit("kilocalorie / (mole * radian ** 2)")
assert pot.parameters["k"].to(
kcal_mol_rad2).magnitude == pytest.approx(2.5)