Lille spectroscopic database for astrophysically and atmospherically relevant molecules

Context . Over past 15 years, we have accumulated a significant amount of data on rotational spectra of astrophysically and atmospherically relevant molecules. These data were mostly absent from main spectroscopic databases, such as CDMS and the JPL catalog, and dispersed across the supplementary sections of various publications. Aims . The aim of the Lille Spectroscopic Database (LSD) is to consolidate the accumulated data from the PhLAM laboratory into a single accessible location, enhancing its availability to the scientific community, and to introduce several additional features that facilitate data utilization. Methods . The LSD is based on a relational database accessible via a Java application that provides front- and back-end features. The application provides data access through a standard web interface and via a set of simple application programming interface (API) functions primarily intended for queries from external tools. Results . The LSD provides access to molecular spectral predictions with options for frequency units, intensity units, temperature, and frequency range limitations. The output also contains partition function values for a set of temperatures. We also present several challenges in the conversion of intensity units inherent to the data output format and in connection with statistical weights and partition function calculation.