ThermodynamicState

class openff.evaluator.thermodynamics.ThermodynamicState(temperature=None, pressure=None)[source]

Data specifying a physical thermodynamic state obeying Boltzmann statistics.

Notes

Equality of two thermodynamic states is determined by comparing the temperature in kelvin to within 3 decimal places, and comparing the pressure (if defined) in pascals to within 3 decimal places.

Examples

Specify an NPT state at 298 K and 1 atm pressure.

>>> state = ThermodynamicState(temperature=298.0*unit.kelvin, pressure=1.0*unit.atmospheres)

Note that the pressure is only relevant for periodic systems.

__init__(temperature=None, pressure=None)[source]

Constructs a new ThermodynamicState object.

Parameters

temperature (openff.evaluator.unit.Quantity) – The external temperature
pressure (openff.evaluator.unit.Quantity) – The external pressure

Methods

`__init__`([temperature, pressure])	Constructs a new ThermodynamicState object.
`from_json`(file_path)	Create this object from a JSON file.
`get_attributes`([attribute_type])	Returns all attributes of a specific attribute_type.
`json`([file_path, format])	Creates a JSON representation of this class.
`parse_json`(string_contents)	Parses a typed json string into the corresponding class structure.
`validate`([attribute_type])	Validate the values of the attributes.

Attributes

`beta`	Returns one divided by the temperature multiplied by the molar gas constant
`inverse_beta`	Returns the temperature multiplied by the molar gas constant
`pressure`	The external pressure.
`temperature`	The external temperature.

property inverse_beta: Returns the temperature multiplied by the molar gas constant

property beta: Returns one divided by the temperature multiplied by the molar gas constant

temperature

The external temperature. The default value of this attribute is not set and must be set by the user..

Type: Quantity

pressure

The external pressure. The default value of this attribute is not set. This attribute is optional.

Type: Quantity

validate(attribute_type=None)[source]

Validate the values of the attributes. If attribute_type is set, only attributes of that type will be validated.

Parameters: attribute_type (type of Attribute, optional) – The type of attribute to validate.
Raises: ValueError or AssertionError –

classmethod from_json(file_path)

Create this object from a JSON file.

Parameters: file_path (str) – The path to load the JSON from.
Returns: The parsed class.
Return type: cls

classmethod get_attributes(attribute_type=None)

Returns all attributes of a specific attribute_type.

Parameters: attribute_type (type of Attribute, optional) – The type of attribute to search for.
Returns: The names of the attributes of the specified type.
Return type: list of str

json(file_path=None, format=False)

Creates a JSON representation of this class.

Parameters

file_path (str, optional) – The (optional) file path to save the JSON file to.
format (bool) – Whether to format the JSON or not.

Returns

The JSON representation of this class.

Return type

str

classmethod parse_json(string_contents)

Parses a typed json string into the corresponding class structure.

Parameters: string_contents (str or bytes) – The typed json string.
Returns: The parsed class.
Return type: Any