class arkane.ess.OrcaLog(path, check_for_errors=True)

Represent an output file from Orca. The attribute path refers to the location on disk of the Orca output file of interest. Methods are provided to extract a variety of information into Arkane classes and/or NumPy arrays. OrcaLog is an adapter for the abstract class ESSAdapter.


Checks for common errors in an Orca log file. If any are found, this method will raise an error and crash.


Returns the D1 diagnostic from output log. If multiple occurrences exist, returns the last occurrence. Should be implemented by the relevant subclass.


Returns the T1 diagnostic from output log. If multiple occurrences exist, returns the last occurrence. T1 diagnostic only available in Coupled Cluster calculations.


Return the number of atoms in the molecular configuration used in the Orca output file.


Return the name of the software. Should correspond to the class name without ‘Log’.


This method uses the symmetry package from RMG’s QM module and returns a tuple where the first element is the number of optical isomers, the second element is the symmetry number, and the third element is the point group identified.

load_conformer(symmetry=None, spin_multiplicity=0, optical_isomers=None, label='')

Load the molecular degree of freedom data from a log file created as the result of an Orca “Freq” quantum chemistry calculation. As Orca’s guess of the external symmetry number is not always correct, you can use the symmetry parameter to substitute your own value; if not provided, the value in the Orca log file will be adopted.


Load the energy in J/ml from an Orca log file. Only the last energy in the file is returned. The zero-point energy is not included in the returned value.


Return the force constant matrix from the Orca log file. Orca prints the Hessian matrix as a ‘.hess’ file which must be located in the same folder as the log file for this method to parse it. The units of the returned force constants are J/m^2. If no force constant matrix can be found, None is returned.


Return the optimum geometry of the molecular configuration from the Orca log file. If multiple such geometries are identified, only the last is returned.


Return the imaginary frequency from a transition state frequency calculation in cm^-1. Since there can be many imaginary frequencies, only the first one is returned.


not implemented in Orca


Not implemented for Orca


Not implemented for Orca


Load the unscaled zero-point energy in J/mol from a Orca output file.