Plot Raman Spectra from Gaussian 16

raman_from_gaussian is a Python toolkit for extracting and plotting Raman spectroscopy results from Gaussian 16 log files. It supports resonance Raman calculations and non-resonance calculations containing several incident-light frequencies.

The spectrum generator builds a frequency grid, extracts the calculated lines, and broadens them with Gaussian, Lorentzian, or mixed line shapes. It displays the result with Matplotlib and writes CSV files so the processed spectrum can be reused in another plotting or analysis workflow.

Basic use

from core import generate_rr_spectrum, generate_nrr_spectrum

generate_rr_spectrum(
    min=0,
    max=4000,
    nstep=8000,
    input_filename="calculation.log",
    lorentzian_width=10,
    gaussian_width=10,
    lorentzian_percentage=1,
)

lorentzian_percentage=1 selects a pure Lorentzian profile; 0 selects a pure Gaussian. The widths are full widths at half maximum in cm⁻¹. The companion notebook demonstrates both calculation types.

The parser expects the relevant Gaussian sections to exist. Resonance work depends on the appropriate Freq=ReadFCHT workflow, while multi-frequency non-resonance output uses freq=raman cphf=rdfreq and incident wavelengths supplied in the input. Confirm the Gaussian job before treating a missing spectrum as a plotting problem.

Visit the raman_from_gaussian repository for the notebook and current extraction code.