arXiv is an e-print service in the fields of physics, mathematics, computer science, quantitative biology, quantitative finance, statistics, electrical engineering and systems science, and economics. It provides access to more the 1.3 million e-prints. The Max Planck Society is a member institution of arXiv.

NMRShiftDB is a web database for organic structures and their nuclear magnetic resonance (nmr) spectra. It allows for spectrum prediction (currently only for carbon) as well as for searching spectra, structures and other properties. Last not least, it features peer-reviewed submission of datasets by its users.

The SSRN eLibrary consists of two parts: an Abstract Database containing abstracts on over 60,500 scholarly working papers and forthcoming papers and an Electronic Paper Collection currently containing over 38,400 downloadable fulltext documents in Adobe Acrobat pdf format. The eLibrary also includes the research papers of a number of Fee Based Partner Publications.

The MPI-Mainz-UV-VIS Spectral Atlas is a comprehensive collection of absorption cross sections for gaseous molecules and radicals, primarily relevant to atmospheric research, from measurements performed during the last nine decades. The individual data sets were collected from the original publications, either copied from tabulations, or read from figures in those cases where numerical data could no longer be obtained. Other sources rely on the internal databases of several research centers dealing with atmospheric chemistry and/or molecular spectroscopy. Numerous excellent high-resolution spectra were obtained from personal communications with the scientists.