# pymatgen.io.qchem.sets module

Input sets for Qchem

class ForceSet(molecule: pymatgen.core.structure.Molecule, basis_set: str = 'def2-tzvppd', scf_algorithm: str = 'diis', dft_rung: int = 3, pcm_dielectric: Optional[float] = None, smd_solvent: Optional[str] = None, custom_smd: Optional[str] = None, max_scf_cycles: int = 200, plot_cubes: bool = False, nbo_params: Optional[Dict] = None, overwrite_inputs: Optional[Dict] = None, vdw_mode: Literal['atomic', 'sequential'] = 'atomic')

  Bases: `pymatgen.io.qchem.sets.QChemDictSet`

  QChemDictSet for a force (gradient) calculation

  Parameters

    - molecule (Pymatgen Molecule object) –

    - basis_set (str) – Basis set to use. (Default: “def2-tzvppd”)

    - scf_algorithm (str) – Algorithm to use for converging the SCF. Recommended choices are “DIIS”, “GDM”, and “DIIS_GDM”. Other algorithms supported by Qchem’s GEN_SCFMAN module will also likely perform well. Refer to the QChem manual for further details. (Default: “diis”)

    - dft_rung (int) –

      Select the DFT functional among 5 recommended levels of theory, in order of increasing accuracy/cost. 1 = B3LYP, 2=B3lYP+D3, 3=ωB97X-D, 4=ωB97X-V, 5=ωB97M-V. (Default: 3)

      To set a functional not given by one of the above, set the overwrite_inputs argument to {“method”:”<NAME OF FUNCTIONAL>”}

      Note that the “rungs” in this argument do NOT correspond to rungs on “Jacob’s Ladder of Density Functional Approxmations”

    - pcm_dielectric (float) – Dielectric constant to use for PCM implicit solvation model. (Default: None)

    - smd_solvent (str) –

      Solvent to use for SMD implicit solvation model. (Default: None) Examples include “water”, “ethanol”, “methanol”, and “acetonitrile”. Refer to the QChem manual for a complete list of solvents available. To define a custom solvent, set this argument to “custom” and populate custom_smd with the necessary parameters.

      Note that only one of smd_solvent and pcm_dielectric may be set.

    - custom_smd (str) – List of parameters to define a custom solvent in SMD. (Default: None) Must be given as a string of seven comma separated values in the following order: “dielectric, refractive index, acidity, basicity, surface tension, aromaticity, electronegative halogenicity” Refer to the QChem manual for further details.

    - max_scf_cycles (int) – Maximum number of SCF iterations. (Default: 200)

    - geom_opt_max_cycles (int) – Maximum number of geometry optimization iterations. (Default: 200)

    - plot_cubes (bool) – Whether to write CUBE files of the electron density. (Default: False)

    - overwrite_inputs (dict) –

      Dictionary of QChem input sections to add or overwrite variables. The currently available sections (keys) are rem, pcm, solvent, smx, opt, scan, van_der_waals, and plots. The value of each key is a dictionary of key value pairs relevant to that section. For example, to add a new variable to the rem section that sets symmetry to false, use

      overwrite_inputs = {“rem”: {“symmetry”: “false”}}

      Note that if something like basis is added to the rem dict it will overwrite the default basis.

      Note that supplying a van_der_waals section here will automatically modify the PCM “radii” setting to “read”.

      Note that all keys must be given as strings, even when they are numbers!

    - vdw_mode ('atomic' | 'sequential') – Method of specifying custom van der Waals radii. Applies only if you are using overwrite_inputs to add a $van_der_waals section to the input. In ‘atomic’ mode (default), dict keys represent the atomic number associated with each radius (e.g., ‘12’ = carbon). In ‘sequential’ mode, dict keys represent the sequential position of a single specific atom in the input structure.

class FreqSet(molecule: pymatgen.core.structure.Molecule, basis_set: str = 'def2-tzvppd', scf_algorithm: str = 'diis', dft_rung: int = 3, pcm_dielectric: Optional[float] = None, smd_solvent: Optional[str] = None, custom_smd: Optional[str] = None, max_scf_cycles: int = 200, plot_cubes: bool = False, nbo_params: Optional[Dict] = None, overwrite_inputs: Optional[Dict] = None, vdw_mode: Literal['atomic', 'sequential'] = 'atomic')

  Bases: `pymatgen.io.qchem.sets.QChemDictSet`

  QChemDictSet for a frequency calculation

  Parameters

    - molecule (Pymatgen Molecule object) –

    - basis_set (str) – Basis set to use. (Default: “def2-tzvppd”)

    - scf_algorithm (str) – Algorithm to use for converging the SCF. Recommended choices are “DIIS”, “GDM”, and “DIIS_GDM”. Other algorithms supported by Qchem’s GEN_SCFMAN module will also likely perform well. Refer to the QChem manual for further details. (Default: “diis”)

    - dft_rung (int) –

      Select the DFT functional among 5 recommended levels of theory, in order of increasing accuracy/cost. 1 = B3LYP, 2=B3lYP+D3, 3=ωB97X-D, 4=ωB97X-V, 5=ωB97M-V. (Default: 3)

      To set a functional not given by one of the above, set the overwrite_inputs argument to {“method”:”<NAME OF FUNCTIONAL>”}

      Note that the “rungs” in this argument do NOT correspond to rungs on “Jacob’s Ladder of Density Functional Approxmations”

    - pcm_dielectric (float) – Dielectric constant to use for PCM implicit solvation model. (Default: None)

    - smd_solvent (str) –

      Solvent to use for SMD implicit solvation model. (Default: None) Examples include “water”, “ethanol”, “methanol”, and “acetonitrile”. Refer to the QChem manual for a complete list of solvents available. To define a custom solvent, set this argument to “custom” and populate custom_smd with the necessary parameters.

      Note that only one of smd_solvent and pcm_dielectric may be set.

    - custom_smd (str) – List of parameters to define a custom solvent in SMD. (Default: None) Must be given as a string of seven comma separated values in the following order: “dielectric, refractive index, acidity, basicity, surface tension, aromaticity, electronegative halogenicity” Refer to the QChem manual for further details.

    - max_scf_cycles (int) – Maximum number of SCF iterations. (Default: 200)

    - geom_opt_max_cycles (int) – Maximum number of geometry optimization iterations. (Default: 200)

    - plot_cubes (bool) – Whether to write CUBE files of the electron density. (Default: False)

    - overwrite_inputs (dict) –

      Dictionary of QChem input sections to add or overwrite variables. The currently available sections (keys) are rem, pcm, solvent, smx, opt, scan, van_der_waals, and plots. The value of each key is a dictionary of key value pairs relevant to that section. For example, to add a new variable to the rem section that sets symmetry to false, use

      overwrite_inputs = {“rem”: {“symmetry”: “false”}}

      Note that if something like basis is added to the rem dict it will overwrite the default basis.

      Note that supplying a van_der_waals section here will automatically modify the PCM “radii” setting to “read”.

      Note that all keys must be given as strings, even when they are numbers!

    - vdw_mode ('atomic' | 'sequential') – Method of specifying custom van der Waals radii. Applies only if you are using overwrite_inputs to add a $van_der_waals section to the input. In ‘atomic’ mode (default), dict keys represent the atomic number associated with each radius (e.g., ‘12’ = carbon). In ‘sequential’ mode, dict keys represent the sequential position of a single specific atom in the input structure.

class OptSet(molecule: pymatgen.core.structure.Molecule, basis_set: str = 'def2-tzvppd', scf_algorithm: str = 'diis', dft_rung: int = 3, pcm_dielectric: Optional[float] = None, smd_solvent: Optional[str] = None, custom_smd: Optional[str] = None, max_scf_cycles: int = 200, plot_cubes: bool = False, nbo_params: Optional[Dict] = None, opt_variables: Optional[Dict[str, List]] = None, geom_opt_max_cycles: int = 200, overwrite_inputs: Optional[Dict] = None, vdw_mode: Literal['atomic', 'sequential'] = 'atomic')

  Bases: `pymatgen.io.qchem.sets.QChemDictSet`

  QChemDictSet for a geometry optimization

  Parameters

    - molecule (Pymatgen Molecule object) –

    - job_type (str) – QChem job type to run. Valid options are “opt” for optimization, “sp” for single point, “freq” for frequency calculation, or “force” for force evaluation.

    - basis_set (str) – Basis set to use. (Default: “def2-tzvppd”)

    - scf_algorithm (str) – Algorithm to use for converging the SCF. Recommended choices are “DIIS”, “GDM”, and “DIIS_GDM”. Other algorithms supported by Qchem’s GEN_SCFMAN module will also likely perform well. Refer to the QChem manual for further details. (Default: “diis”)

    - dft_rung (int) –

      Select the DFT functional among 5 recommended levels of theory, in order of increasing accuracy/cost. 1 = B3LYP, 2=B3lYP+D3, 3=ωB97X-D, 4=ωB97X-V, 5=ωB97M-V. (Default: 3)

      To set a functional not given by one of the above, set the overwrite_inputs argument to {“method”:”<NAME OF FUNCTIONAL>”}

      Note that the “rungs” in this argument do NOT correspond to rungs on “Jacob’s Ladder of Density Functional Approxmations”

    - pcm_dielectric (float) – Dielectric constant to use for PCM implicit solvation model. (Default: None)

    - smd_solvent (str) –

      Solvent to use for SMD implicit solvation model. (Default: None) Examples include “water”, “ethanol”, “methanol”, and “acetonitrile”. Refer to the QChem manual for a complete list of solvents available. To define a custom solvent, set this argument to “custom” and populate custom_smd with the necessary parameters.

      Note that only one of smd_solvent and pcm_dielectric may be set.

    - custom_smd (str) – List of parameters to define a custom solvent in SMD. (Default: None) Must be given as a string of seven comma separated values in the following order: “dielectric, refractive index, acidity, basicity, surface tension, aromaticity, electronegative halogenicity” Refer to the QChem manual for further details.

    - max_scf_cycles (int) – Maximum number of SCF iterations. (Default: 200)

    - geom_opt_max_cycles (int) – Maximum number of geometry optimization iterations. (Default: 200)

    - plot_cubes (bool) – Whether to write CUBE files of the electron density. (Default: False)

    - overwrite_inputs (dict) –

      Dictionary of QChem input sections to add or overwrite variables. The currently available sections (keys) are rem, pcm, solvent, smx, opt, scan, van_der_waals, and plots. The value of each key is a dictionary of key value pairs relevant to that section. For example, to add a new variable to the rem section that sets symmetry to false, use

      overwrite_inputs = {“rem”: {“symmetry”: “false”}}

      Note that if something like basis is added to the rem dict it will overwrite the default basis.

      Note that supplying a van_der_waals section here will automatically modify the PCM “radii” setting to “read”.

      Note that all keys must be given as strings, even when they are numbers!

    - vdw_mode ('atomic' | 'sequential') – Method of specifying custom van der Waals radii. Applies only if you are using overwrite_inputs to add a $van_der_waals section to the input. In ‘atomic’ mode (default), dict keys represent the atomic number associated with each radius (e.g., ‘12’ = carbon). In ‘sequential’ mode, dict keys represent the sequential position of a single specific atom in the input structure.

class PESScanSet(molecule: pymatgen.core.structure.Molecule, basis_set: str = 'def2-tzvppd', scf_algorithm: str = 'diis', dft_rung: int = 3, pcm_dielectric: Optional[float] = None, smd_solvent: Optional[str] = None, custom_smd: Optional[str] = None, max_scf_cycles: int = 200, plot_cubes: bool = False, nbo_params: Optional[Dict] = None, opt_variables: Optional[Dict[str, List]] = None, scan_variables: Optional[Dict[str, List]] = None, overwrite_inputs: Optional[Dict] = None, vdw_mode: Literal['atomic', 'sequential'] = 'atomic')

  Bases: `pymatgen.io.qchem.sets.QChemDictSet`

  QChemDictSet for a potential energy surface scan (PES_SCAN) calculation, used primarily to identify possible transition states or to sample different geometries. Note: Because there are no defaults that can be used for a PES scan (the variables are completely dependent on the molecular structure), by default scan_variables = None. However, a PES Scan job should not be run with less than one variable (or more than two variables).

  Parameters

    - molecule (Pymatgen Molecule object) –

    - opt_variables (dict) –

      A dictionary of opt sections, where each opt section is a key and the corresponding values are a list of strings. Stings must be formatted as instructed by the QChem manual. The different opt sections are: CONSTRAINT, FIXED, DUMMY, and CONNECT.

      Ex. opt = {“CONSTRAINT”: [“tors 2 3 4 5 25.0”, “tors 2 5 7 9 80.0”], “FIXED”: [“2 XY”]}

    - scan_variables (dict) –

      A dictionary of scan variables. Because two constraints of the same type are allowed (for instance, two torsions or two bond stretches), each TYPE of variable (stre, bend, tors) should be its own key in the dict, rather than each variable. Note that the total number of variable (sum of lengths of all lists) CANNOT be more than two.

      Ex. scan_variables = {“stre”: [“3 6 1.5 1.9 0.1”], “tors”: [“1 2 3 4 -180 180 15”]}

    - basis_set (str) – Basis set to use. (Default: “def2-tzvppd”)

    - scf_algorithm (str) – Algorithm to use for converging the SCF. Recommended choices are “DIIS”, “GDM”, and “DIIS_GDM”. Other algorithms supported by Qchem’s GEN_SCFMAN module will also likely perform well. Refer to the QChem manual for further details. (Default: “diis”)

    - dft_rung (int) –

      Select the DFT functional among 5 recommended levels of theory, in order of increasing accuracy/cost. 1 = B3LYP, 2=B3lYP+D3, 3=ωB97X-D, 4=ωB97X-V, 5=ωB97M-V. (Default: 3)

      To set a functional not given by one of the above, set the overwrite_inputs argument to {“method”:”<NAME OF FUNCTIONAL>”}

      Note that the “rungs” in this argument do NOT correspond to rungs on “Jacob’s Ladder of Density Functional Approxmations”

    - pcm_dielectric (float) – Dielectric constant to use for PCM implicit solvation model. (Default: None)

    - smd_solvent (str) –

      Solvent to use for SMD implicit solvation model. (Default: None) Examples include “water”, “ethanol”, “methanol”, and “acetonitrile”. Refer to the QChem manual for a complete list of solvents available. To define a custom solvent, set this argument to “custom” and populate custom_smd with the necessary parameters.

      Note that only one of smd_solvent and pcm_dielectric may be set.

    - custom_smd (str) – List of parameters to define a custom solvent in SMD. (Default: None) Must be given as a string of seven comma separated values in the following order: “dielectric, refractive index, acidity, basicity, surface tension, aromaticity, electronegative halogenicity” Refer to the QChem manual for further details.

    - max_scf_cycles (int) – Maximum number of SCF iterations. (Default: 200)

    - geom_opt_max_cycles (int) – Maximum number of geometry optimization iterations. (Default: 200)

    - plot_cubes (bool) – Whether to write CUBE files of the electron density. (Default: False)

    - overwrite_inputs (dict) –

      Dictionary of QChem input sections to add or overwrite variables. The currently available sections (keys) are rem, pcm, solvent, smx, opt, scan, van_der_waals, and plots. The value of each key is a dictionary of key value pairs relevant to that section. For example, to add a new variable to the rem section that sets symmetry to false, use

      overwrite_inputs = {“rem”: {“symmetry”: “false”}}

      Note that if something like basis is added to the rem dict it will overwrite the default basis.

      Note that supplying a van_der_waals section here will automatically modify the PCM “radii” setting to “read”.

      Note that all keys must be given as strings, even when they are numbers!

    - vdw_mode ('atomic' | 'sequential') – Method of specifying custom van der Waals radii. Applies only if you are using overwrite_inputs to add a $van_der_waals section to the input. In ‘atomic’ mode (default), dict keys represent the atomic number associated with each radius (e.g., ‘12’ = carbon). In ‘sequential’ mode, dict keys represent the sequential position of a single specific atom in the input structure.

class QChemDictSet(molecule: pymatgen.core.structure.Molecule, job_type: str, basis_set: str, scf_algorithm: str, dft_rung: int = 4, pcm_dielectric: Optional[float] = None, smd_solvent: Optional[str] = None, custom_smd: Optional[str] = None, opt_variables: Optional[Dict[str, List]] = None, scan_variables: Optional[Dict[str, List]] = None, max_scf_cycles: int = 200, geom_opt_max_cycles: int = 200, plot_cubes: bool = False, nbo_params: Optional[Dict] = None, overwrite_inputs: Optional[Dict] = None, vdw_mode: Literal['atomic', 'sequential'] = 'atomic')

  Bases: `pymatgen.io.qchem.inputs.QCInput`

  Build a QCInput given all the various input parameters. Can be extended by standard implementations below.

  Parameters

    - molecule (Pymatgen Molecule object) –

    - job_type (str) – QChem job type to run. Valid options are “opt” for optimization, “sp” for single point, “freq” for frequency calculation, or “force” for force evaluation.

    - basis_set (str) – Basis set to use. For example, “def2-tzvpd”.

    - scf_algorithm (str) – Algorithm to use for converging the SCF. Recommended choices are “DIIS”, “GDM”, and “DIIS_GDM”. Other algorithms supported by Qchem’s GEN_SCFMAN module will also likely perform well. Refer to the QChem manual for further details.

    - dft_rung (int) –

      Select the DFT functional among 5 recommended levels of theory, in order of increasing accuracy/cost. 1 = B3LYP, 2=B3lYP+D3, 3=ωB97X-D, 4=ωB97X-V, 5=ωB97M-V. (Default: 4)

      To set a functional not given by one of the above, set the overwrite_inputs argument to {“method”:”<NAME OF FUNCTIONAL>”}

      Note that the “rungs” in this argument do NOT correspond to rungs on “Jacob’s Ladder of Density Functional Approxmations”

    - pcm_dielectric (float) – Dielectric constant to use for PCM implicit solvation model. (Default: None)

    - smd_solvent (str) –

      Solvent to use for SMD implicit solvation model. (Default: None) Examples include “water”, “ethanol”, “methanol”, and “acetonitrile”. Refer to the QChem manual for a complete list of solvents available. To define a custom solvent, set this argument to “custom” and populate custom_smd with the necessary parameters.

      Note that only one of smd_solvent and pcm_dielectric may be set.

    - custom_smd (str) – List of parameters to define a custom solvent in SMD. (Default: None) Must be given as a string of seven comma separated values in the following order: “dielectric, refractive index, acidity, basicity, surface tension, aromaticity, electronegative halogenicity” Refer to the QChem manual for further details.

    - opt_variables (dict) –

      A dictionary of opt sections, where each opt section is a key and the corresponding values are a list of strings. Stings must be formatted as instructed by the QChem manual. The different opt sections are: CONSTRAINT, FIXED, DUMMY, and CONNECT.

      Ex. opt = {“CONSTRAINT”: [“tors 2 3 4 5 25.0”, “tors 2 5 7 9 80.0”], “FIXED”: [“2 XY”]}

    - scan_variables (dict) –

      A dictionary of scan variables. Because two constraints of the same type are allowed (for instance, two torsions or two bond stretches), each TYPE of variable (stre, bend, tors) should be its own key in the dict, rather than each variable. Note that the total number of variable (sum of lengths of all lists) CANNOT be more than two.

      Ex. scan_variables = {“stre”: [“3 6 1.5 1.9 0.1”], “tors”: [“1 2 3 4 -180 180 15”]}

    - max_scf_cycles (int) – Maximum number of SCF iterations. (Default: 200)

    - geom_opt_max_cycles (int) – Maximum number of geometry optimization iterations. (Default: 200)

    - plot_cubes (bool) – Whether to write CUBE files of the electron density. (Default: False)

    - nbo_params (list) – A list of strings for the desired NBO params. If an empty list is passed, default NBO analysis will be performed. (Default: False)

    - overwrite_inputs (dict) –

      Dictionary of QChem input sections to add or overwrite variables. The currently available sections (keys) are rem, pcm, solvent, smx, opt, scan, van_der_waals, and plots. The value of each key is a dictionary of key value pairs relevant to that section. For example, to add a new variable to the rem section that sets symmetry to false, use

      overwrite_inputs = {“rem”: {“symmetry”: “false”}}

      Note that if something like basis is added to the rem dict it will overwrite the default basis.

      Note that supplying a van_der_waals section here will automatically modify the PCM “radii” setting to “read”.

      Note that all keys must be given as strings, even when they are numbers!

    - vdw_mode ('atomic' | 'sequential') – Method of specifying custom van der Waals radii. Applies only if you are using overwrite_inputs to add a $van_der_waals section to the input. In ‘atomic’ mode (default), dict keys represent the atomic number associated with each radius (e.g., ‘12’ = carbon). In ‘sequential’ mode, dict keys represent the sequential position of a single specific atom in the input structure.

  write(input_file: str)
    Parameters

      input_file (str) – Filename

class SinglePointSet(molecule: pymatgen.core.structure.Molecule, basis_set: str = 'def2-tzvppd', scf_algorithm: str = 'diis', dft_rung: int = 3, pcm_dielectric: Optional[float] = None, smd_solvent: Optional[str] = None, custom_smd: Optional[str] = None, max_scf_cycles: int = 200, plot_cubes: bool = False, nbo_params: Optional[Dict] = None, overwrite_inputs: Optional[Dict] = None, vdw_mode: Literal['atomic', 'sequential'] = 'atomic')

  Bases: `pymatgen.io.qchem.sets.QChemDictSet`

  QChemDictSet for a single point calculation

  Parameters

    - molecule (Pymatgen Molecule object) –

    - job_type (str) – QChem job type to run. Valid options are “opt” for optimization, “sp” for single point, “freq” for frequency calculation, or “force” for force evaluation.

    - basis_set (str) – Basis set to use. (Default: “def2-tzvppd”)

    - scf_algorithm (str) – Algorithm to use for converging the SCF. Recommended choices are “DIIS”, “GDM”, and “DIIS_GDM”. Other algorithms supported by Qchem’s GEN_SCFMAN module will also likely perform well. Refer to the QChem manual for further details. (Default: “diis”)

    - dft_rung (int) –

      Select the DFT functional among 5 recommended levels of theory, in order of increasing accuracy/cost. 1 = B3LYP, 2=B3lYP+D3, 3=ωB97X-D, 4=ωB97X-V, 5=ωB97M-V. (Default: 3)

      To set a functional not given by one of the above, set the overwrite_inputs argument to {“method”:”<NAME OF FUNCTIONAL>”}

      Note that the “rungs” in this argument do NOT correspond to rungs on “Jacob’s Ladder of Density Functional Approxmations”

    - pcm_dielectric (float) – Dielectric constant to use for PCM implicit solvation model. (Default: None)

    - smd_solvent (str) –

      Solvent to use for SMD implicit solvation model. (Default: None) Examples include “water”, “ethanol”, “methanol”, and “acetonitrile”. Refer to the QChem manual for a complete list of solvents available. To define a custom solvent, set this argument to “custom” and populate custom_smd with the necessary parameters.

      Note that only one of smd_solvent and pcm_dielectric may be set.

    - custom_smd (str) – List of parameters to define a custom solvent in SMD. (Default: None) Must be given as a string of seven comma separated values in the following order: “dielectric, refractive index, acidity, basicity, surface tension, aromaticity, electronegative halogenicity” Refer to the QChem manual for further details.

    - max_scf_cycles (int) – Maximum number of SCF iterations. (Default: 200)

    - plot_cubes (bool) – Whether to write CUBE files of the electron density. (Default: False)

    - overwrite_inputs (dict) –

      Dictionary of QChem input sections to add or overwrite variables. The currently available sections (keys) are rem, pcm, solvent, smx, opt, scan, van_der_waals, and plots. The value of each key is a dictionary of key value pairs relevant to that section. For example, to add a new variable to the rem section that sets symmetry to false, use

      overwrite_inputs = {“rem”: {“symmetry”: “false”}}

      Note that if something like basis is added to the rem dict it will overwrite the default basis.

      Note that supplying a van_der_waals section here will automatically modify the PCM “radii” setting to “read”.

      Note that all keys must be given as strings, even when they are numbers!

    - vdw_mode ('atomic' | 'sequential') – Method of specifying custom van der Waals radii. Applies only if you are using overwrite_inputs to add a $van_der_waals section to the input. In ‘atomic’ mode (default), dict keys represent the atomic number associated with each radius (e.g., ‘12’ = carbon). In ‘sequential’ mode, dict keys represent the sequential position of a single specific atom in the input structure.

class TransitionStateSet(molecule: pymatgen.core.structure.Molecule, basis_set: str = 'def2-tzvppd', scf_algorithm: str = 'diis', dft_rung: int = 3, pcm_dielectric: Optional[float] = None, smd_solvent: Optional[str] = None, custom_smd: Optional[str] = None, max_scf_cycles: int = 200, plot_cubes: bool = False, nbo_params: Optional[Dict] = None, opt_variables: Optional[Dict[str, List]] = None, geom_opt_max_cycles: int = 200, overwrite_inputs: Optional[Dict] = None, vdw_mode='atomic')

  Bases: `pymatgen.io.qchem.sets.QChemDictSet`

  QChemDictSet for a transition-state search

  Parameters

    - molecule (Pymatgen Molecule object) –

    - basis_set (str) – Basis set to use. (Default: “def2-tzvppd”)

    - scf_algorithm (str) – Algorithm to use for converging the SCF. Recommended choices are “DIIS”, “GDM”, and “DIIS_GDM”. Other algorithms supported by Qchem’s GEN_SCFMAN module will also likely perform well. Refer to the QChem manual for further details. (Default: “diis”)

    - dft_rung (int) –

      Select the DFT functional among 5 recommended levels of theory, in order of increasing accuracy/cost. 1 = B3LYP, 2=B3lYP+D3, 3=ωB97X-D, 4=ωB97X-V, 5=ωB97M-V. (Default: 3)

      To set a functional not given by one of the above, set the overwrite_inputs argument to {“method”:”<NAME OF FUNCTIONAL>”}

      Note that the “rungs” in this argument do NOT correspond to rungs on “Jacob’s Ladder of Density Functional Approxmations”

    - pcm_dielectric (float) – Dielectric constant to use for PCM implicit solvation model. (Default: None)

    - smd_solvent (str) –

      Solvent to use for SMD implicit solvation model. (Default: None) Examples include “water”, “ethanol”, “methanol”, and “acetonitrile”. Refer to the QChem manual for a complete list of solvents available. To define a custom solvent, set this argument to “custom” and populate custom_smd with the necessary parameters.

      Note that only one of smd_solvent and pcm_dielectric may be set.

    - custom_smd (str) – List of parameters to define a custom solvent in SMD. (Default: None) Must be given as a string of seven comma separated values in the following order: “dielectric, refractive index, acidity, basicity, surface tension, aromaticity, electronegative halogenicity” Refer to the QChem manual for further details.

    - max_scf_cycles (int) – Maximum number of SCF iterations. (Default: 200)

    - geom_opt_max_cycles (int) – Maximum number of geometry optimization iterations. (Default: 200)

    - plot_cubes (bool) – Whether to write CUBE files of the electron density. (Default: False)

    - overwrite_inputs (dict) –

      Dictionary of QChem input sections to add or overwrite variables. The currently available sections (keys) are rem, pcm, solvent, smx, opt, scan, van_der_waals, and plots. The value of each key is a dictionary of key value pairs relevant to that section. For example, to add a new variable to the rem section that sets symmetry to false, use

      overwrite_inputs = {“rem”: {“symmetry”: “false”}}

      Note that if something like basis is added to the rem dict it will overwrite the default basis.

      Note that supplying a van_der_waals section here will automatically modify the PCM “radii” setting to “read”.

      Note that all keys must be given as strings, even when they are numbers!

    - vdw_mode ('atomic' | 'sequential') – Method of specifying custom van der Waals radii. Applies only if you are using overwrite_inputs to add a $van_der_waals section to the input. In ‘atomic’ mode (default), dict keys represent the atomic number associated with each radius (e.g., ‘12’ = carbon). In ‘sequential’ mode, dict keys represent the sequential position of a single specific atom in the input structure.