Sesam is a project sustained by LERMA (Laboratoire d’Etudes du Rayonnement et de la Matière). Its purpose is to provide a molecular spectroscopy database dedicated to electronic spectra of diatomic molecules. The structure of the database has been fostered with the tools developed within the VAMDC (Virtual Atomic and Molecular Data Center) project.

The different spectral quantities are described in xml format, following the concepts set up in the XSAMS group. The purpose of such an effort is to provide full interoperability of the data for different user communities and applications. The data are of interest for the interpretation of spectral VUV observations or/and plasma spectroscopy as well as for modeling tools.

Sesam has largely benefited from the availability of the MOLAT database and is intended to extend and replace it as far as molecular hydrogen data are concerned. The data will be kept as homogeneous as possible. Users of Sesam are asked to refer to the original publications. They could also mention the following sentence in the acknowledgements of the research papers: “The (some) spectroscopic data used have been downloaded from the online Sesam Database (