arc.level

A module for working with levels of theory.

class arc.level.Level(repr: Optional[Union[str, dict, Level]] = None, method: Optional[str] = None, basis: Optional[str] = None, auxiliary_basis: Optional[str] = None, dispersion: Optional[str] = None, cabs: Optional[str] = None, method_type: Optional[str] = None, software: Optional[str] = None, software_version: Optional[Union[int, float, str]] = None, compatible_ess: Optional[List[str]] = None, solvation_method: Optional[str] = None, solvent: Optional[str] = None, solvation_scheme_level: Optional[Level] = None, args: Optional[Union[Dict[str, str], Iterable, str]] = None)

Uniquely defines the settings used for a quantum calculation level of theory. Either repr or method must be specified.

Parameters:

• repr (str, dict, Level optional) – A dictionary or a simple string representation of the level of theory, e.g. “wb97xd/def2-tzvp”, or {‘method’: ‘b3lyp’, ‘basis’: ‘6-31g’}. Not in LevelOfTheory.

• method (str, optional) – Quantum chemistry method.

• basis (str, optional) – Basis set.

• auxiliary_basis (str, optional) – Auxiliary basis set for correlated methods.

• dispersion (str, optional) – The DFT dispersion info (if not already included in method).

• cabs (str, optional) – Complementary auxiliary basis set for F12 calculations.

• method_type (str, optional) – The level of theory method type (DFT, wavefunction, force field, semi-empirical, or composite). Not in LevelOfTheory.

• software (str, optional) – Quantum chemistry software.

• software_version (Union[int, float, str], optional) – Quantum chemistry software version.

• solvation_method (str, optional) – Solvation method.

• solvent (str, optional) – The solvent. Values are strings of “known” solvents, see https://gaussian.com/scrf/.

• solvation_scheme_level (Level, optional) – A Level class representing the level of theory to calculate a solvation energy correction at. Not in LevelOfTheory.

• args (Dict[Dict[str, str]], optional) – Additional arguments provided to the software. Different than the args in LevelOfTheory.

• compatible_ess (list, optional) – Entries are names of compatible ESS. Not in LevelOfTheory.

as_dict() → dict

Returns a minimal dictionary representation from which the object can be reconstructed. Useful for ARC restart files.

build()

Assign object attributes from a dictionary representation of the object or a simple string (“method/basis”). Useful for ARC restart files.

copy()

A method to create a copy of the object.

Returns:

A copy of the object.

Return type:

Level

deduce_method_type()

Determine the type of a model chemistry: DFT, wavefunction, force field, semi-empirical, or composite

deduce_software(job_type: Optional[str] = None)

Deduce the ESS to be used for a given level of theory. Populates the .software attribute.

Parameters:

job_type (str, optional) – An ARC job type, assists in determining the software.

determine_compatible_ess()

Determine compatible ESS.

lower()

Set arguments to lowercase.

simple() → str

Return a simple humane-readable string representation of the object.

Returns:

The simple level of theory string representation.

Return type:

str

to_arkane_level_of_theory(variant: Optional[str] = None, bac_type: str = 'p', comprehensive: bool = False, raise_error: bool = False, warn: bool = True) → Optional[LevelOfTheory]

Convert Level to an Arkane LevelOfTheory instance.

Parameters:

• variant (str, optional) – Return a variant of the Arkane LevelOfTheory that matches an Arkane query. Allowed values are 'freq', 'AEC', 'BEC'. Returns None if no functioning variant was found.

• bac_type (str, optional) – The BAC type (‘p’ or ‘m’) to use when searching for a LevelOfTheory variant for BAC.

• comprehensive (bool, optional) – Whether to consider all relevant arguments if not looking for a variant.

• raise_error (bool, optional) – Whether to raise an error if an AEC variant could not be found.

• warn (bool, optional) – Whether to output a warning if an AEC variant could not be found.

Returns:

The respective Arkane LevelOfTheory object

Return type:

Optional[LevelOfTheory]

arc.level.assign_frequency_scale_factor(level: Union[str, Level]) → Optional[int]

Assign a frequency scaling factor to a level of theory.

Parameters:

level (Union[str, Level]) – The level of theory.

Returns:

The frequency scaling factor.

Return type:

Optional[int]

arc.level.get_params_from_arkane_level_of_theory_as_str(arkane_level: str) → Dict[str, str]

Get the method, basis set, and software (if any) of an str representation of an Arkane LevelOfTheory object instance.

Parameters:

arkane_level (str) – The Arkane level.

Returns:

Keys are ‘method’, ‘basis’, ‘software’.

Return type:

Dict[str, str]