tqchem.xtb_api

Attributes

XTB_METHODS

Functions

xtb_singlepoint(molecule[, method, charge])

Performs a single-point energy calculation using xTB.

xtb_optimize(molecule[, method, charge])

Optimizes the molecular structure using xTB.

read_xtb_vibspectrum(filename)

Reads the vibrational spectrum from an xTB output file.

xtb_ir_spectrum(molecule[, method, charge])

Calculates the IR spectrum of a molecule using xTB.

Module Contents

tqchem.xtb_api.XTB_METHODS: _typeshed.Incomplete
tqchem.xtb_api.xtb_singlepoint(molecule: tqchem.molgraph.MolecularSystem, method: str = 'gfn1-xtb', charge: int = 0)

Performs a single-point energy calculation using xTB.

Parameters:

  • molecule (MolecularSystem) – The molecular structure to perform the calculation on.

  • method (str, optional) – The xTB method to use. Defaults to “gfn1-xtb”.

  • charge (int, optional) – The charge of the molecule. Defaults to 0.

Returns:

energy – The total energy of the molecule in Eh, or None if the energy could not be extracted.

Return type:

float or None

tqchem.xtb_api.xtb_optimize(molecule: tqchem.molgraph.MolecularSystem, method: str = 'gfn1-xtb', charge: int = 0)

Optimizes the molecular structure using xTB.

Parameters:

  • molecule (MolecularSystem) – The molecular structure to perform the optimization on.

  • method (str, optional) – The xTB method to use. Defaults to “gfn1-xtb”.

  • charge (int, optional) – The charge of the molecule. Defaults to 0.

Returns:

  • molecule_opt (MolecularSystem) – The optimized molecular structure.

  • energy (float or None) – The total energy of the molecule in Eh, or None if the energy could not be extracted.

tqchem.xtb_api.read_xtb_vibspectrum(filename: str)

Reads the vibrational spectrum from an xTB output file.

Parameters:

filename (str) – The path to the file containing the vibrational spectrum data.

Returns:

  • frequencies (list) – A list of vibrational frequencies in wave numbers.

  • intensities (list) – A list of IR intensities corresponding to the frequencies.

tqchem.xtb_api.xtb_ir_spectrum(molecule: tqchem.molgraph.MolecularSystem, method: str = 'gfn-xtb', charge: int = 0)

Calculates the IR spectrum of a molecule using xTB.

Parameters:

  • molecule (MolecularSystem) – The molecular structure to calculate the IR spectrum for.

  • method (str, optional) – The xTB method to use for the calculation. Defaults to “gfn-xtb”.

  • charge (int, optional) – The charge of the molecule. Defaults to 0.

Returns:

  • frequencies (list) – A list of vibrational frequencies in wave numbers.

  • intensities (list) – A list of IR intensities corresponding to the frequencies.