# openforcefield.typing.engines.smirnoff.parameters.ToolkitAM1BCCHandler

class `openforcefield.typing.engines.smirnoff.parameters.``ToolkitAM1BCCHandler`(**kwargs)

  Handle SMIRNOFF `<ToolkitAM1BCC>` tags

  Warning

  This API is experimental and subject to change.

  Attributes
    `known_kwargs`

      List of kwargs that can be parsed by the function.

    `parameters`

      The ParameterList that holds this ParameterHandler’s parameter objects

  Methods

  `add_parameter`(parameter_kwargs) | Add a parameter to the forcefield, ensuring all parameters are valid.
  `assign_charge_from_molecules`(molecule, …) | Given an input molecule, checks against a list of molecules for an isomorphic match.
  `assign_parameters`(topology, system) | Assign parameters for the given Topology to the specified System object.
  `check_handler_compatibility`(handler_kwargs) | Checks if a set of kwargs used to create a ParameterHandler are compatible with this ParameterHandler.
  `check_parameter_compatibility`(parameter_kwargs) | Check to make sure that the fields requiring defined units are compatible with the required units for the Parameters handled by this ParameterHandler
  `find_matches`(entity) | Find the elements of the topology/molecule matched by a parameter type.
  `get_parameter`(parameter_attrs) | Return the parameters in this ParameterHandler that match the parameter_attrs argument
  `postprocess_system`(system, topology, **kwargs) | Allow the force to perform a a final post-processing pass on the System following parameter assignment, if needed.
  `to_dict`([output_units, …]) | Convert this ParameterHandler to an OrderedDict, compliant with the SMIRNOFF data spec.

  create_force |

  `__init__`(**kwargs)

    Initialize a ParameterHandler, optionally with a list of parameters and other kwargs.

    Parameters
      permit_cosmetic_attributes bool

        Whether to accept non-spec kwargs

      **kwargs dict

        The dict representation of the SMIRNOFF data source

  Methods

  `__init__`(**kwargs) | Initialize a ParameterHandler, optionally with a list of parameters and other kwargs.
  `add_parameter`(parameter_kwargs) | Add a parameter to the forcefield, ensuring all parameters are valid.
  `assign_charge_from_molecules`(molecule, …) | Given an input molecule, checks against a list of molecules for an isomorphic match.
  `assign_parameters`(topology, system) | Assign parameters for the given Topology to the specified System object.
  `check_handler_compatibility`(handler_kwargs) | Checks if a set of kwargs used to create a ParameterHandler are compatible with this ParameterHandler.
  `check_parameter_compatibility`(parameter_kwargs) | Check to make sure that the fields requiring defined units are compatible with the required units for the Parameters handled by this ParameterHandler
  `create_force`(system, topology, **kwargs) |
  `find_matches`(entity) | Find the elements of the topology/molecule matched by a parameter type.
  `get_parameter`(parameter_attrs) | Return the parameters in this ParameterHandler that match the parameter_attrs argument
  `postprocess_system`(system, topology, **kwargs) | Allow the force to perform a a final post-processing pass on the System following parameter assignment, if needed.
  `to_dict`([output_units, …]) | Convert this ParameterHandler to an OrderedDict, compliant with the SMIRNOFF data spec.

  Attributes

  `known_kwargs` | List of kwargs that can be parsed by the function.
  `parameters` | The ParameterList that holds this ParameterHandler’s parameter objects

  `check_handler_compatibility`(handler_kwargs, assume_missing_is_default=True)

    Checks if a set of kwargs used to create a ParameterHandler are compatible with this ParameterHandler. This is called if a second handler is attempted to be initialized for the same tag. If no value is given for a field, it will be assumed to expect the ParameterHandler class default.

    Parameters
      handler_kwargs dict

        The kwargs that would be used to construct a ParameterHandler

      assume_missing_is_default bool

        If True, will assume that parameters not specified in handler_kwargs would have been set to the default. Therefore, an exception is raised if the ParameterHandler is incompatible with the default value for a unspecified field.

    Raises
      IncompatibleParameterError if handler_kwargs are incompatible with existing parameters.
  `assign_charge_from_molecules`(molecule, charge_mols)

    Given an input molecule, checks against a list of molecules for an isomorphic match. If found, assigns partial charges from the match to the input molecule.

    Parameters
      molecule an openforcefield.topology.FrozenMolecule

        The molecule to have partial charges assigned if a match is found.

      charge_mols list of [openforcefield.topology.FrozenMolecule]

        A list of molecules with charges already assigned.

    Returns
      match_found bool

        Whether a match was found. If True, the input molecule will have been modified in-place.

  `postprocess_system`(system, topology, **kwargs)

    Allow the force to perform a a final post-processing pass on the System following parameter assignment, if needed.

    Parameters
      topology openforcefield.topology.Topology

        The Topology for which parameters are to be assigned. Either a new Force will be created or parameters will be appended to an existing Force.

      system simtk.openmm.System

        The OpenMM System object to add the Force (or append new parameters) to.

  `add_parameter`(parameter_kwargs)

    Add a parameter to the forcefield, ensuring all parameters are valid.

    Parameters
      parameter_kwargs dict

        The kwargs to pass to the ParameterHandler.INFOTYPE (a ParameterType) constructor

  `assign_parameters`(topology, system)

    Assign parameters for the given Topology to the specified System object.

    Parameters
      topology openforcefield.topology.Topology

        The Topology for which parameters are to be assigned. Either a new Force will be created or parameters will be appended to an existing Force.

      system simtk.openmm.System

        The OpenMM System object to add the Force (or append new parameters) to.

  `check_parameter_compatibility`(parameter_kwargs)

    Check to make sure that the fields requiring defined units are compatible with the required units for the Parameters handled by this ParameterHandler

    Parameters
      parameter_kwargs: dict

        The dict that will be used to construct the ParameterType

    Raises
      Raises a ValueError if the parameters are incompatible.
  `find_matches`(entity)

    Find the elements of the topology/molecule matched by a parameter type.

    Parameters
      entity openforcefield.topology.Topology or openforcefield.topology.Molecule

        Topology or molecule to search.

    Returns
      matches ValenceDict[Tuple[int], ParameterType]

        `matches[particle_indices]` is the `ParameterType` object matching the tuple of particle indices in `entity`.

  `get_parameter`(parameter_attrs)

    Return the parameters in this ParameterHandler that match the parameter_attrs argument

    Parameters
      parameter_attrs dict of {attr: value}

        The attrs mapped to desired values (for example {“smirks”: “[:1]~[#16:2]=,:[#6:3]~[:4]”, “id”: “t105”} )

    Returns
      list of ParameterType-derived objects

        A list of matching ParameterType-derived objects

  `known_kwargs`

    List of kwargs that can be parsed by the function.

  `parameters`

    The ParameterList that holds this ParameterHandler’s parameter objects

  `to_dict`(output_units=None, return_cosmetic_attributes=False)

    Convert this ParameterHandler to an OrderedDict, compliant with the SMIRNOFF data spec.

    Parameters
      output_units dict[str

        A mapping from the ParameterType attribute name to the output unit its value should be converted to.

      return_cosmetic_attributes bool, optional. Default = False.

        Whether to return non-spec parameter and header attributes in this ParameterHandler.

    Returns
      smirnoff_data OrderedDict

        SMIRNOFF-spec compliant representation of this ParameterHandler and its internal ParameterList.