Several concerns were raised in a private email by Paul Labute (CCG) about Sage 2.1:
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t49 vs t84
t49 "*~[#7a]:[#6a:3]~*" in Sage 2.1.- seems to be handled by later t84; should t49 be deleted?
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We can verify this by inspecting the training dataset to see which molecules need t49 (results are shown in this notebook
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Therefore, ost aromatic N atoms are treated by t84, but t49 is not redundant, as it applies to aromatic charged N.
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from openff.toolkit import Molecule, ForceField, Topology forcefield = ForceField("openff-2.1.0.offxml") import tqdm from qcportal.client import FractalClient from openff.qcsubmit.results import TorsionDriveResultCollection # Create a client which allows us to connect to the main QCArchive server. qcarchive_client = FractalClient() td_result_collection = TorsionDriveResultCollection.parse_file( "sage-2.1.0/inputs-and-outputs/data-sets/td-set-for-fitting-2.1.0.json" ) records_and_molecules = td_result_collection.to_records() use_t49 = [] # list of molecules that use t49 for _, molecule in tqdm.tqdm(records_and_molecules, desc="checking"): all_labels = forcefield.label_molecules(molecule.to_topology()) for mol_idx, mol_forces in enumerate(all_labels): for force_tag, force_dict in mol_forces.items(): for atom_indices, parameter in force_dict.items(): atomstr = "" for idx in atom_indices: atomstr += "%3s" % idx # for some reason this adds each molecule 4 times for each appearance of t49 if parameter.id == 't49': use_t49.append(molecule.to_smiles()) # Create unique list of molecules that use t49 set_list = set(use_t49) use_t49_unique = list(set_list) # Visualize the molecules Molecule.from_smiles(use_t49_unique[0]) Molecule.from_smiles(use_t49_unique[1]) Molecule.from_smiles(use_t49_unique[2]) |
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It appears that no molecules in the training set use t123, which would make it redundant (at least based on this dataset).
It also appears that no molecules in the OpenFF Industry Benchmark Season 1 v1.1 or OpenFF-benchmark-ligand-fragments-v1.0 datasets use t123, as seen in this notebook
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t129
Covered 47 times by Sage 2.1.0/td-set-for-fitting.json and by my filtered version and by my filtered version with torsion multiplicity additions. These 47 torsions cover the 13 molecules here:
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And shown with their SMILES here:
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The lingering question is whether or not the large force constant is justified by the torsion potential energy surface.
PESs
To answer this, below are the molecules for which the TorsionDriveRecord
dihedrals match the SMIRKS for t129 in the training data set:
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Each pair of images shows the molecule on the left, and the corresponding torsion drive scan on the right.
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From these data the force constant value of -20 kcal/mol looks reasonable and could even be a bit low for these cases.