This example demonstrates how to compare parm@frosst energies of molecules from the AlkEthOH set between systems generated from a SMIRNOFF .offxml file and systems generated from AMBER prmtop/inpcrd files.
- compare_molecule_energies.py: compare energies for a single molecule
- compare_set_energies.py: compare energies across a set of molecules
The key idea here is to use the utility compare_system_energies to compare the molecule parameterized by ForceField with a corresponding system constructed via an AMBER prmtop/inpcrd pair:
# Load molecule
from openmmtools.topology import Molecule
molecule = Molecule.from_file(mol_filename)
# Load force field
from openff.toolkit.typing.engines.smirnoff import ForceField
forcefield = ForceField(offxml_filename)
# Compare energies
from openff.toolkit.tests.utils import compare_molecule_energies
energies = compare_amber_smirnoff(prmtop_filename, inpcrd_filename, forcefield, molecule)