A Journey With <scp>THeSeuSS</scp>: Automated Python Tool for Modeling <scp>IR</scp> and Raman Vibrational Spectra of Molecules and Solids

ABSTRACT Vibrational spectroscopy is an indispensable analytical tool that provides structural fingerprints for molecules, solids, and interfaces thereof. This study introduces THeSeuSS (THz Spectra Simulations Software)—an automated computational platform that efficiently simulates IR and Raman spectra for both periodic and non‐periodic systems. Using DFT, DFTB and machine‐learning force field, THeSeuSS offers robust capabilities for detailed vibrational spectra simulations. Our extensive evaluations and benchmarks demonstrate that THeSeuSS accurately reproduces both previously calculated and experimental spectra, enabling precise comparisons and interpretations of vibrational characteristics in various test cases, including H 2 O and glycine molecules in the gas phase, as well as solid ammonia and solid ibuprofen. Designed with a user‐friendly interface and seamless integration with existing computational chemistry tools, THeSeuSS enhances the accessibility and applicability of advanced spectroscopic simulations, supporting research and development in chemical, pharmaceutical, and material sciences.