Source code for qiskit_nature.second_q.drivers.gaussiand.gaussian_forces_driver

# This code is part of a Qiskit project.
# (C) Copyright IBM 2020, 2023.
# This code is licensed under the Apache License, Version 2.0. You may
# obtain a copy of this license in the LICENSE.txt file in the root directory
# of this source tree or at
# Any modifications or derivative works of this code must retain this
# copyright notice, and modified files need to carry a notice indicating
# that they have been altered from the originals.

""" Gaussian Forces Driver """

from __future__ import annotations

from typing import Any
from qiskit_nature import QiskitNatureError

from qiskit_nature.units import DistanceUnit
from qiskit_nature.second_q.formats.molecule_info import MoleculeInfo
from qiskit_nature.second_q.formats.watson_translator import watson_to_problem
from qiskit_nature.second_q.problems import VibrationalBasis, VibrationalStructureProblem
import qiskit_nature.optionals as _optionals

from .gaussian_log_driver import GaussianLogDriver
from .gaussian_log_result import GaussianLogResult
from ..vibrational_structure_driver import VibrationalStructureDriver

#p B3LYP/cc-pVTZ Freq=(Anharm) Int=Ultrafine SCF=VeryTight

CO2 geometry optimization B3LYP/cc-pVTZ

0 1
C        -0.848629    2.067624    0.160992
O         0.098816    2.655801   -0.159738
O        -1.796073    1.479446    0.481721


[docs]class GaussianForcesDriver(VibrationalStructureDriver): """Gaussian™ 16 forces driver.""" def __init__( self, jcf: str | list[str] = B3YLP_JCF_DEFAULT, logfile: str | None = None, *, normalize: bool = True, ) -> None: r""" Args: jcf: A job control file conforming to Gaussian™ 16 format. This can be provided as a single string with '\\n' line separators or as a list of strings. logfile: Instead of a job control file a log as output from running such a file can optionally be given. normalize: Whether to normalize the factors used in creation of the VibrationalEnergy as returned when this driver is run. Raises: QiskitNatureError: If `jcf` given and Gaussian™ 16 executable cannot be located. """ super().__init__() self._jcf = jcf self._logfile = None self._normalize = normalize # Logfile has precedence if supplied if logfile is not None: self._jcf = None self._logfile = logfile # If running from a jcf we need Gaussian™ 16 so check if we have a # valid install. if self._logfile is None: _optionals.HAS_GAUSSIAN.require_now("GaussianForcesDriver __init__")
[docs] @staticmethod @_optionals.HAS_GAUSSIAN.require_in_call def from_molecule( molecule: MoleculeInfo, *, basis: str = "sto-3g", xcf: str = "B3LYP", driver_kwargs: dict[str, Any] | None = None, ) -> "GaussianForcesDriver": """Creates a driver from a molecule. Args: molecule: If a molecule is supplied then an appropriate job control file will be built from this, and the `basis`, and will be used in precedence of either the `logfile` or the `jcf` params. basis: The basis set to be used in the resultant job control file when a molecule is provided. xcf: The exchange-correlation functional to be used in the resultant job control file. driver_kwargs: keyword arguments to be passed to driver. Returns: The constructed driver instance. Raises: QiskitNatureError: when an unknown unit is encountered. """ # Ignore kwargs parameter for this driver del driver_kwargs basis = GaussianForcesDriver.to_driver_basis(basis) if molecule.units == DistanceUnit.ANGSTROM: units = "Angstrom" elif molecule.units == DistanceUnit.BOHR: units = "Bohr" else: raise QiskitNatureError(f"Unknown unit '{molecule.units.value}'") cfg1 = f"#p {xcf}/{basis} UNITS={units} Freq=(Anharm) Int=Ultrafine SCF=VeryTight\n\n" name = "".join(molecule.symbols) geom = "\n".join( [ name + " " + " ".join(map(str, coord)) for (name, coord) in zip(molecule.symbols, molecule.coords) ] ) cfg2 = f"{name} geometry optimization\n\n" cfg3 = f"{molecule.charge} {molecule.multiplicity}\n{geom}\n\n" return GaussianForcesDriver(jcf=cfg1 + cfg2 + cfg3)
[docs] @staticmethod def to_driver_basis(basis: str) -> str: """Converts basis to a driver acceptable basis. Args: basis: The basis set to be used. Returns: A driver acceptable basis. """ if basis == "sto3g": return "sto-3g" return basis
[docs] def run(self, basis: VibrationalBasis) -> VibrationalStructureProblem: # type: ignore[override] # pylint: disable=arguments-differ if self._logfile is not None: glr = GaussianLogResult(self._logfile) else: glr = GaussianLogDriver(jcf=self._jcf).run() watson = glr.get_watson_hamiltonian(normalize=self._normalize) problem = watson_to_problem(watson, basis=basis) return problem