orca module¶

The aim of the orca module is to provide several class in order to read or write ORCA output or input files.

Orca input file¶

class orca.OrcaInput(mol, charge=None, spin_multiplicity=None, input_parameters=None, blocks=None)[source]¶

An object representing an Orca input file.

Parameters:

Parameters:	mol – Input molecule. If molecule is a single string, it is used as a direct input to the geometry section of the input file. charge (float) – Charge of the molecule. If None, charge on molecule is used. Defaults to None. This allows the input file to be set a charge independently from the molecule itself. spin_multiplicity (float) – Spin multiplicity of molecule. Defaults to None, which means that the spin multiplicity is set to 1 if the molecule has no unpaired electrons and to 2 if there are unpaired electrons. input_parameters (list) – Input parameters for run as a list blocks (list) – Blocks input for advanced settings as a list of string. The block has to be already well formatted.

mol – Input molecule. If molecule is a single string, it is used as a direct input to the geometry section of the input file.
charge (float) – Charge of the molecule. If None, charge on molecule is used. Defaults to None. This allows the input file to be set a charge independently from the molecule itself.
spin_multiplicity (float) – Spin multiplicity of molecule. Defaults to None, which means that the spin multiplicity is set to 1 if the molecule has no unpaired electrons and to 2 if there are unpaired electrons.
input_parameters (list) – Input parameters for run as a list
blocks (list) – Blocks input for advanced settings as a list of string. The block has to be already well formatted.

get_string()[source]¶: Return a string representation of the input file

molecule¶: Returns molecule associated with this OrcaInput.

Orca Hessian file¶

class orca.OrcaHessian(filename)[source]¶

Parser for ORCA Hessian file. All data are in atomic units.

Parameters:	filename – Filename of ORCA hessian file.

filename¶: Path to the ORCA Hessian file

energy¶: Energy in Hartree.

molecule¶: The molecule geometry read in the hessian file. Coordinates are read in atomic unit and store in the molecule object in atomic units.

frequencies¶

A list of dict for each frequencies with

{
    "frequency": freq in cm-1,
    "symmetry": symmetry tag
    "r_mass": Reduce mass,
    "f_constant": force constant,
    "IR_intensity": IR Intensity,
    "mode": normal mode
 }

The normal mode is a 1D vector of dx, dy dz of each atom.

hessian¶: Matrix of second derivatives of the energy with respect to cartesian coordinates in the input orientation frame. Need #P in the route section in order to be in the output.

get_mol_ang(inplace=False)[source]¶

Return a new Molecule object with coordinate in angstrom

Parameters:	inplace (bool) – if True, do operation inplace and return None.

symmetrize_hessian(inplace=False)[source]¶

Return a symmetrized hessian matrix.

Parameters:	inplace (bool) – if True, do operation inplace and return None.

Orca output file¶

class orca.OrcaOutfile(filename)[source]¶

Parser for ORCA output file.

Parameters:	filename – Filename of Orca output file.

filename¶: Path to the ORCA Output file

number_electrons¶: Total number of electrons in the system

number_basis_functions¶: Number of contracted basis functions in the main gaussian basis set.

nuclear_repulsion¶: Nuclear repulsion energy of the last geometry.

charge¶: Total charge of the molecule.

spin_multiplicity¶: Spin multiplicity of the molecule.

mul_charges¶: List of the last Mulliken atomic charges. If a geometry optimization is done, only the last charges are saved.

loe_charges¶: List of the Loewdin atomic charges. If a geometry optimization is done, only the last charges are saved.

hirshfeld_charges¶: List of the Hirshfeld atomic charges. If a geometry optimization is done, only the last charges are saved.

esp_charges¶: List of the ESP charges fitted on the electrostatic potential. Use CHELPG in the input file to get that charges.

mul_spin_pop¶: List of the last Mulliken spin populations. If a geometry optimization is done, only the last spin populations are saved.

loe_spin_pop¶: List of the last Loewdin spin populations. If a geometry optimization is done, only the last spin populations are saved.

hirshfeld_spin_pop¶: List of the last Hirshfeld spin populations. If a geometry optimization is done, only the last spin populations are saved.

orca_input¶: An OrcaInput instance created from the input file read on the Orca outfile. The considered structure is the last one.

bond_orders¶: Dict of bond order values read in the output file such as: {(0, 1): 0.8709, (1, 6): 1.234, …}

dipole_moment¶: Components of the dipole moment in a.u.

dipole¶: Magnitude of the dipole moment in Debye

structures¶: List of all structures in the calculation as pymatgen.Molecule object. The last geometry for the last additionnal SCF calculation is included.

is_spin¶: True if the calculation is a unrestricted calculation (UKS) in INPUT. False if the calculation is a restricted calculation.

optimization_converged¶: None if Opt is not in INPUT. True if optimization converge else False.

normal_termination¶: True if Orca terminated normally.

temperature¶: Temperature, in Kelvin, for the calculations of thermochemical quantities

pressure¶: Pressure, in atmosphere, for the calculations of thermochemical quantities

mass¶: Total mass, in AMU (g.mol-1), for the calculations of themochemical quantities

frequencies¶: List of vibrational frequencies in cm-1

thermo_data¶: dictionnary of all thermochemistry data read in output file. [‘electronic energy’, ‘zero point energy’, ‘thermal vibrational correction’,

‘thermal rotational correction’, ‘thermal translational correction’, ‘inner energy’, ‘thermal enthalpy correction’, ‘total enthalpy’, ‘electronic entropy’, ‘vibrational entropy’, ‘rotational entropy’, ‘translational entropy’, ‘total entropy correction’, ‘final gibbs free enthalpy’, ‘g-e(el)’, ‘entropy’]

mo_energies¶: Dict of the molecular orbital energies for each spin (if relevant) such as {Spin.up: energies, Spin.down: energies}

mo_occupations¶: Dict of molecular orbital occupations for each spin (if relevant) such as {Spin.up: occupations, Spin.down: occupations}

mo_matrix¶: Dict of arrays of molecular orbital coefficients for each spin (if relevant). The shapes of the arrays are (number_basis_functions x number_basis_functions). {Spin.up: coefficients, Spin.down: coefficients}

final_energy¶: Last SCF energy

final_structure¶: last geometry

gibbs_free_enthalpy¶: Gibbs free enthalpy in kcal.mol-1

homo¶

Highest Occupied Molecular Orbital

Type:	HOMO

initial_structure¶: first geometry

lumo¶

Lowest Unoccupied Molecular Orbital

Type:	LUMO

mo_dataframe¶

dataframe, Spin.down: dataframe}

Each column of the data frame is a MO. Each row contains the coefficients for an atom, in a specfic AO.

Type:	A dict of data frames with MO coefficients such as
Type:	{Spin.up

Orca VPT2 file¶

class orca.OrcaVPT2(filename)[source]¶

Parser for ORCA .vpt2 file.

Parameters:	filename – Filename of ORCA .vpt2 file.

filename¶: Path to the ORCA .vpt2 file

settings¶: VPT2 calculation settings.

molecule¶: The molecule geometry read in the hessian file. Coordinates are read in atomic unit and store in the molecule object in atomic units.

hessian¶: Hessian matrix in Eh/(bohr**2). Array shape (3N, 3N)

dipole_derivative¶: Dipole derivatives in (Eh * bohr)^(1/2). Array shape (3N, 3)

cubic_terms¶: Cubic force field in cm-1. Array shape (3N-6, 3N-6, 3N-6)

semi_quartic_terms¶: Semi-quartic force field in cm-1. Only [i][j][k][k] terms are provided. The last index is not repeated. Thus the shape of the array is (3N-6, 3N-6, 3N-6)