A reproducible Python workflow for absorber–light-source spectral matching: overlap-calculator

Abstract

A reproducible Python workflow for absorber-light-source spectral matching: overlap-calculator Pinar Seyitdanlioglu* aThe spectral compatibility between an organic absorber and the illumination source is an important but often underquantified descriptor in computational screening of organic photovoltaic materials, particularly for indoor applications where light sources have narrow and source-dependent emission profiles. Here, we introduce overlap-calculator, an opensource Python workflow for reproducible batch analysis of spectral overlap between molecular absorption spectra and solar or indoor reference light sources. The workflow accepts Gaussian TD-DFT output files and tabular UV-vis spectra in CSV or Excel formats within a common manifest-driven pipeline. TD-DFT transitions are reconstructed into continuous absorption profiles using Gaussian and Lorentzian broadening, converted into absorptance through a Beer-Lambert treatment, and compared with AM1.5G, CIE LED, fluorescent, or user-supplied spectra. The resulting descriptors include absorbed flux, absorbed fraction, and max-normalised shape overlap. The workflow is demonstrated using five previously generated TD-DFT OPV candidate absorbers and eight public organic UV-vis spectra used as spreadsheet-input examples. The TD-DFT case study illustrates automated transition parsing, spectral reconstruction, and source-dependent ranking, whereas the spreadsheet-input case demonstrates that tabular UV-vis data can be processed through the same descriptor-generation pipeline. By converting a previously script-based interpretation step into a documented and reusable workflow with command-line, API, Docker, and structured-output support, overlap-calculator provides a practical tool for transparent spectral-compatibility analysis in data-driven optoelectronic materials research.