# rmgpy.cantherm.gaussian.GaussianLog¶

class rmgpy.cantherm.gaussian.GaussianLog(path)

Represent a log file from Gaussian. The attribute path refers to the location on disk of the Gaussian log file of interest. Methods are provided to extract a variety of information into CanTherm classes and/or NumPy arrays.

getNumberOfAtoms()

Return the number of atoms in the molecular configuration used in the Gaussian log file.

loadConformer(symmetry=None, spinMultiplicity=None, opticalIsomers=1)

Load the molecular degree of freedom data from a log file created as the result of a Gaussian “Freq” quantum chemistry calculation. As Gaussian’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 Gaussian log file will be adopted. In a log file with multiple Thermochemistry sections, only the last one will be kept.

loadEnergy(frequencyScaleFactor=1.0)

Load the energy in J/mol from a Gaussian log file. The file is checked for a complete basis set extrapolation; if found, that value is returned. Only the last energy in the file is returned. The zero-point energy is not included in the returned value; it is removed from the CBS-QB3 value.

loadForceConstantMatrix()

Return the force constant matrix from the Gaussian log file. The job that generated the log file must have the option iop(7/33=1) in order for the proper force constant matrix (in Cartesian coordinates) to be printed in the log file. If multiple such matrices are identified, only the last is returned. The units of the returned force constants are J/m^2. If no force constant matrix can be found in the log file, None is returned.

loadGeometry()

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

loadNegativeFrequency()

Return the negative frequency from a transition state frequency calculation in cm^-1.

loadScanEnergies()

Extract the optimized energies in J/mol from a log file, e.g. the result of a Gaussian “Scan” quantum chemistry calculation.

loadZeroPointEnergy()

Load the unscaled zero-point energy in J/mol from a Gaussian log file.