Merge pull request #759 from openforcefield/cleaner-openmm-nonbonded

Clean up internal processing of non-bonded data to OpenMM

openff/interchange/_tests/unit_tests/interop/openmm/test_nonbonded.py

@@ -0,0 +1,35 @@
+import pytest
+from openff.toolkit import Molecule
+from openff.units import unit
+
+from openff.interchange._tests import _BaseTest
+from openff.interchange.exceptions import UnsupportedCutoffMethodError
+
+
+class TestUnsupportedCases(_BaseTest):
+    def test_ljpme_nonperiodic(self, sage):
+        interchange = sage.create_interchange(Molecule.from_smiles("CC").to_topology())
+
+        interchange["vdW"].method = "pme"
+
+        with pytest.raises(
+            UnsupportedCutoffMethodError,
+            match="not valid for non-periodic systems",
+        ):
+            interchange.to_openmm(combine_nonbonded_forces=False)
+
+    @pytest.mark.parametrize("periodic", [True, False])
+    def test_reaction_field(self, sage, periodic):
+        interchange = sage.create_interchange(Molecule.from_smiles("CC").to_topology())
+
+        if periodic:
+            interchange.box = [4, 4, 4] * unit.nanometer
+            interchange["Electrostatics"].periodic_potential = "reaction-field"
+        else:
+            interchange["Electrostatics"].nonperiodic_potential = "reaction-field"
+
+        with pytest.raises(
+            UnsupportedCutoffMethodError,
+            match="Reaction field electrostatics not supported. ",
+        ):
+            interchange.to_openmm(combine_nonbonded_forces=False)