energy

Train against relative energies and forces.

Classes:

• Entry –

  Represents a set of reference energies and forces.

Functions:

• create_dataset –

  Create a dataset from a list of existing entries.

• extract_smiles –

  Return a list of unique SMILES strings in the dataset.

• predict –

  Predict the relative energies [kcal/mol] and forces [kcal/mol/Å] of a dataset.

Entry

Bases: TypedDict

Represents a set of reference energies and forces.

Attributes:

• smiles (str) –

  The indexed SMILES description of the molecule the energies and forces were

• coords (Tensor) –

  The coordinates [Å] the energies and forces were evaluated at with

• energy (Tensor) –

  The reference energies [kcal/mol] with shape=(n_confs,).

• forces (Tensor) –

  The reference forces [kcal/mol/Å] with shape=(n_confs, n_particles, 3).

smiles instance-attribute

smiles: str

The indexed SMILES description of the molecule the energies and forces were computed for.

coords instance-attribute

coords: Tensor

The coordinates [Å] the energies and forces were evaluated at with shape=(n_confs, n_particles, 3).

energy instance-attribute

energy: Tensor

The reference energies [kcal/mol] with shape=(n_confs,).

forces instance-attribute

forces: Tensor

The reference forces [kcal/mol/Å] with shape=(n_confs, n_particles, 3).

create_dataset

create_dataset(entries: list[Entry]) -> Dataset

Create a dataset from a list of existing entries.

Parameters:

• entries (list[Entry]) –

  The entries to create the dataset from.

Returns:

• Dataset –

  The created dataset.

Source code in descent/targets/energy.py

def create_dataset(entries: list[Entry]) -> datasets.Dataset:
    """Create a dataset from a list of existing entries.

    Args:
        entries: The entries to create the dataset from.

    Returns:
        The created dataset.
    """

    table = pyarrow.Table.from_pylist(
        [
            {
                "smiles": entry["smiles"],
                "coords": torch.tensor(entry["coords"]).flatten().tolist(),
                "energy": torch.tensor(entry["energy"]).flatten().tolist(),
                "forces": torch.tensor(entry["forces"]).flatten().tolist(),
            }
            for entry in entries
        ],
        schema=DATA_SCHEMA,
    )
    # TODO: validate rows
    dataset = datasets.Dataset(datasets.table.InMemoryTable(table))
    dataset.set_format("torch")

    return dataset

extract_smiles

extract_smiles(dataset: Dataset) -> list[str]

Return a list of unique SMILES strings in the dataset.

Parameters:

• dataset (Dataset) –

  The dataset to extract the SMILES strings from.

Returns:

• list[str] –

  The list of unique SMILES strings.

Source code in descent/targets/energy.py

def extract_smiles(dataset: datasets.Dataset) -> list[str]:
    """Return a list of unique SMILES strings in the dataset.

    Args:
        dataset: The dataset to extract the SMILES strings from.

    Returns:
        The list of unique SMILES strings.
    """
    return sorted({*dataset.unique("smiles")})

predict

predict(
    dataset: Dataset,
    force_field: TensorForceField,
    topologies: dict[str, TensorTopology],
    reference: Literal["mean", "min"] = "mean",
    normalize: bool = True,
) -> tuple[Tensor, Tensor, Tensor, Tensor]

Predict the relative energies [kcal/mol] and forces [kcal/mol/Å] of a dataset.

Parameters:

• dataset (Dataset) –

  The dataset to predict the energies and forces of.

• force_field (TensorForceField) –

  The force field to use to predict the energies and forces.

• topologies (dict[str, TensorTopology]) –

  The topologies of the molecules in the dataset. Each key should be a fully indexed SMILES string.

• reference (Literal['mean', 'min'], default: 'mean' ) –

  The reference energy to compute the relative energies with respect to. This should be either the "mean" energy of all conformers, or the energy of the conformer with the lowest reference energy ("min").

• normalize (bool, default: True ) –

  Whether to scale the relative energies by 1/sqrt(n_confs_i) and the forces by 1/sqrt(n_confs_i * n_atoms_per_conf_i * 3) This is useful when wanting to compute the MSE per entry.

Returns:

• tuple[Tensor, Tensor, Tensor, Tensor] –

  The predicted and reference relative energies [kcal/mol] with shape=(n_confs,), and predicted and reference forces [kcal/mol/Å] with shape=(n_confs * n_atoms_per_conf, 3).

Source code in descent/targets/energy.py

def predict(
    dataset: datasets.Dataset,
    force_field: smee.TensorForceField,
    topologies: dict[str, smee.TensorTopology],
    reference: typing.Literal["mean", "min"] = "mean",
    normalize: bool = True,
) -> tuple[torch.Tensor, torch.Tensor, torch.Tensor, torch.Tensor]:
    """Predict the relative energies [kcal/mol] and forces [kcal/mol/Å] of a dataset.

    Args:
        dataset: The dataset to predict the energies and forces of.
        force_field: The force field to use to predict the energies and forces.
        topologies: The topologies of the molecules in the dataset. Each key should be
            a fully indexed SMILES string.
        reference: The reference energy to compute the relative energies with respect
            to. This should be either the "mean" energy of all conformers, or the
            energy of the conformer with the lowest reference energy ("min").
        normalize: Whether to scale the relative energies by ``1/sqrt(n_confs_i)``
            and the forces by ``1/sqrt(n_confs_i * n_atoms_per_conf_i * 3)`` This
            is useful when wanting to compute the MSE per entry.

    Returns:
        The predicted and reference relative energies [kcal/mol] with
        ``shape=(n_confs,)``, and predicted and reference forces [kcal/mol/Å] with
        ``shape=(n_confs * n_atoms_per_conf, 3)``.
    """
    energy_ref_all, energy_pred_all = [], []
    forces_ref_all, forces_pred_all = [], []

    for entry in dataset:
        smiles = entry["smiles"]

        energy_ref = entry["energy"]
        forces_ref = entry["forces"].reshape(len(energy_ref), -1, 3)

        coords_flat = smee.utils.tensor_like(
            entry["coords"], force_field.potentials[0].parameters
        )

        coords = (
            coords_flat.reshape(len(energy_ref), -1, 3)
        ).detach().requires_grad_(True)
        topology = topologies[smiles]

        energy_pred = smee.compute_energy(topology, force_field, coords)
        forces_pred = -torch.autograd.grad(
            energy_pred.sum(),
            coords,
            create_graph=True,
            retain_graph=True,
            allow_unused=True,
        )[0]

        if reference.lower() == "mean":
            energy_ref_0 = energy_ref.mean()
            energy_pred_0 = energy_pred.mean()
        elif reference.lower() == "min":
            min_idx = energy_ref.argmin()

            energy_ref_0 = energy_ref[min_idx]
            energy_pred_0 = energy_pred[min_idx]
        else:
            raise NotImplementedError(f"invalid reference energy {reference}")

        scale_energy, scale_forces = 1.0, 1.0

        if normalize:
            scale_energy = 1.0 / torch.sqrt(torch.tensor(energy_pred.numel()))
            scale_forces = 1.0 / torch.sqrt(torch.tensor(forces_pred.numel()))

        energy_ref_all.append(scale_energy * (energy_ref - energy_ref_0))
        forces_ref_all.append(scale_forces * forces_ref.reshape(-1, 3))

        energy_pred_all.append(scale_energy * (energy_pred - energy_pred_0))
        forces_pred_all.append(scale_forces * forces_pred.reshape(-1, 3))

    energy_pred_all = torch.cat(energy_pred_all)
    forces_pred_all = torch.cat(forces_pred_all)

    energy_ref_all = torch.cat(energy_ref_all)
    energy_ref_all = smee.utils.tensor_like(energy_ref_all, energy_pred_all)

    forces_ref_all = torch.cat(forces_ref_all)
    forces_ref_all = smee.utils.tensor_like(forces_ref_all, forces_pred_all)

    return (
        energy_ref_all,
        energy_pred_all,
        forces_ref_all,
        forces_pred_all,
    )