SpectroIBIS: Automated Data Processing for Multiconformer Quantum Chemical Spectroscopic Calculations

Quantum chemical spectroscopic calculations have grown increasingly popular in natural products research for aiding the elucidation of chemical structures, especially their stereochemical configurations. These calculations have become faster with modern computational speeds, but subsequent data handling, inspection, and presentation remain key bottlenecks for many researchers. In this article, we introduce the SpectroIBIS computer program as a user-friendly tool to automate tedious tasks commonly encountered in this workflow. Through a simple graphical user interface, researchers can drag and drop Gaussian or ORCA output files to produce Boltzmann-averaged ECD, VCD, UV-vis and IR data, optical rotations, and/or ¹H and ¹³C NMR chemical shifts in seconds. Also produced are formatted, publication-quality supplementary data tables containing conformer energies and atomic coordinates, saved to a DOCX file compatible with Microsoft Word and LibreOffice. Importantly, SpectroIBIS can assist researchers in finding common calculation issues by automatically checking for redundant conformers and imaginary frequencies. Additional useful features include recognition of conformer energy recalculations at a higher theory level, and automated generation of input files for quantum chemistry programs with optional exclusion of high-energy conformers. Lastly, we demonstrate the applicability of SpectroIBIS with spectroscopic calculations for five natural products. SpectroIBIS is open-source software available as a free desktop application (https://github.com/bbulcock/SpectroIBIS).