Merge pull request #873 from openforcefield/test-plugin-energy

Improve energy testing with plugins

.pre-commit-config.yaml

@@ -12,7 +12,7 @@ repos:
   hooks:
   - id: add-trailing-comma
 - repo: https://github.com/psf/black
-  rev: 24.4.0
+  rev: 24.4.2
   hooks:
   - id: black
     files: ^openff|plugins|stubs
@@ -46,7 +46,7 @@ repos:
     exclude: openff/interchange/_version.py|setup.py
     args: ["--py310-plus"]
 - repo: https://github.com/astral-sh/ruff-pre-commit
-  rev: v0.4.1
+  rev: v0.4.2
   hooks:
     - id: ruff
       args: ["check", "--select", "NPY"]

openff/interchange/_tests/unit_tests/drivers/test_openmm.py

@@ -1,15 +1,35 @@
+from copy import deepcopy
+
 import pytest
-from openff.utilities.utilities import has_package, requires_package
+from openff.toolkit import ForceField, Quantity
+from openff.utilities.utilities import has_package
 
+from openff.interchange._tests import MoleculeWithConformer, get_test_file_path
 from openff.interchange.constants import kj_mol
-from openff.interchange.drivers.openmm import _process
+from openff.interchange.drivers.openmm import _process, get_openmm_energies
 
 if has_package("openmm"):
     import openmm
 
 
-@requires_package("openmm")
+@pytest.fixture
+def methane_dimer(sage):
+    molecule = MoleculeWithConformer.from_smiles("C")
+    topology = deepcopy(molecule).to_topology()
+
+    molecule._conformers[0] += Quantity([4, 0, 0], "angstrom")
+
+    topology.add_molecule(molecule)
+
+    interchange = sage.create_interchange(topology)
+    interchange.minimize()
+
+    return interchange
+
+
 class TestProcess:
+    pytest.importorskip("openmm")
+
     @pytest.fixture
     def dummy_system(self):
         system = openmm.System()
@@ -73,3 +93,68 @@ def test_split_forces(self, dummy_system_split):
         assert processed["Electrostatics 1-4"].m_as(kj_mol) == -3
         assert processed["vdW"].m_as(kj_mol) == -1
         assert processed["vdW 1-4"].m_as(kj_mol) == -2
+
+
+class TestReportWithPlugins:
+    pytest.importorskip("smirnoff_plugins")
+    pytest.importorskip("openeye")
+
+    @pytest.fixture
+    def ligand(self):
+        return MoleculeWithConformer.from_smiles("CC[C@@](/C=C\\[H])(C=C)O")
+
+    @pytest.fixture
+    def de_force_field(self) -> ForceField:
+        return ForceField(
+            get_test_file_path("de-force-1.0.1.offxml"),
+            load_plugins=True,
+        )
+
+    @pytest.mark.parametrize("detailed", [True, False])
+    def test_nonzero_vdw(self, ligand, de_force_field, detailed):
+        energies = get_openmm_energies(
+            de_force_field.create_interchange(ligand.to_topology()),
+            combine_nonbonded_forces=False,
+            detailed=detailed,
+        )
+
+        assert energies["vdW"].m != 0
+
+        if detailed:
+            assert energies["vdW 1-4"].m != 0
+
+    def test_detailed_same_total_energy(self, ligand, de_force_field):
+        assert get_openmm_energies(
+            de_force_field.create_interchange(ligand.to_topology()),
+            combine_nonbonded_forces=False,
+            detailed=True,
+        ).total_energy.m == pytest.approx(
+            get_openmm_energies(
+                de_force_field.create_interchange(ligand.to_topology()),
+                combine_nonbonded_forces=False,
+                detailed=False,
+            ).total_energy.m,
+        )
+
+    def test_intermolecular_plugin_vdw_energies_reported(
+        self,
+        de_force_field,
+        methane_dimer,
+    ):
+        new_interchange = de_force_field.create_interchange(methane_dimer.topology)
+        new_interchange.positions = methane_dimer.positions
+
+        new_interchange.minimize(
+            engine="openmm",
+            force_tolerance=Quantity(0.01, "kilojoule_per_mole / nanometer"),
+        )
+
+        energies = get_openmm_energies(
+            new_interchange,
+            combine_nonbonded_forces=False,
+            detailed=True,
+        )
+
+        # vdW (non-LJ) interaction energy should be slightly negative; for comparison,
+        # sage number is -1.377 kJ/mol
+        assert -5 < energies["vdW"].m_as(kj_mol) < -1