`VirtualSiteType`

class openff.toolkit.typing.engines.smirnoff.parameters.VirtualSiteType(**kwargs)

Store virtual site parameters (geometry and electrostatics) and vdW interactions.

__init__(**kwargs)

Create a ParameterType.

Parameters:

smirks – The SMIRKS match for the provided parameter type.
allow_cosmetic_attributes – Whether to permit non-spec kwargs (“cosmetic attributes”). If True, non-spec kwargs will be stored as an attribute of this parameter which can be accessed and written out. Otherwise an exception will be raised.

Methods

`__init__`(**kwargs)	Create a ParameterType.
`add_cosmetic_attribute`(attr_name, attr_value)	Add a cosmetic attribute to this object.
`attribute_is_cosmetic`(attr_name)	Determine whether an attribute of this object is cosmetic.
`delete_cosmetic_attribute`(attr_name)	Delete a cosmetic attribute from this object.
`to_dict`([discard_cosmetic_attributes, ...])	Convert this object to dict format.
`type_to_parent_index`(type_)	Returns the index of the atom matched by the SMIRKS pattern that should be considered the 'parent' to a given type of virtual site.

Attributes

`charge_increment`
`distance`
`epsilon`
`id`
`inPlaneAngle`
`match`
`name`
`outOfPlaneAngle`
`parent_id`
`parent_index`	Returns the index of the atom matched by the SMIRKS pattern that should be considered the 'parent' to the virtual site.
`rmin_half`
`sigma`
`smirks`
`type`

add_cosmetic_attribute(attr_name, attr_value)

Add a cosmetic attribute to this object.

This attribute will not have a functional effect on the object in the OpenFF Toolkit, but can be written out during output.

Warning

The API for modifying cosmetic attributes is experimental and may change in the future (see issue #338).

Parameters:

attr_name – Name of the attribute to define for this object.
attr_value – The value of the attribute to define for this object.

attribute_is_cosmetic(attr_name)

Determine whether an attribute of this object is cosmetic.

Warning

The API for modifying cosmetic attributes is experimental and may change in the future (see issue #338).

Parameters:: attr_name – The attribute name to check
Returns:: is_cosmetic – Returns True if the attribute is defined and is cosmetic. Returns False otherwise.

delete_cosmetic_attribute(attr_name)

Delete a cosmetic attribute from this object.

Warning

The API for modifying cosmetic attributes is experimental and may change in the future (see issue #338).

Parameters:: attr_name – Name of the cosmetic attribute to delete.

property parent_index: int: Returns the index of the atom matched by the SMIRKS pattern that should be considered the ‘parent’ to the virtual site. A value of 0 corresponds to the atom matched by the :1 selector in the SMIRKS pattern, a value 2 the atom matched by :2 and so on.

to_dict(discard_cosmetic_attributes=False, duplicate_attributes=None)

Convert this object to dict format.

The returning dictionary contains all the ParameterAttribute and IndexedParameterAttribute as well as cosmetic attributes if discard_cosmetic_attributes is False.

Parameters:

discard_cosmetic_attributes – Whether to discard non-spec attributes of this object
duplicate_attributes – A list of names of attributes that redundantly decsribe data and should be discarded during serializaiton

Returns:

smirnoff_dict – The SMIRNOFF-compliant dict representation of this object.

classmethod type_to_parent_index(type_: Literal['BondCharge', 'MonovalentLonePair', 'DivalentLonePair', 'TrivalentLonePair']) → int: Returns the index of the atom matched by the SMIRKS pattern that should be considered the ‘parent’ to a given type of virtual site. A value of 0 corresponds to the atom matched by the :1 selector in the SMIRKS pattern, a value 2 the atom matched by :2 and so on.