Each of the 371 databases of BioCyc describes the genome and metabolic pathways of a single organism. The BioCyc databases are divided into 3 tiers, based on their quality: Tier 1: 3 Databases, which have been created through intensive manual efforts and receive continuous updating: 1) *EcoCyc* describes the model organism Escherichia coli K-12. 2) *MetaCyc* describes metabolic pathways and enzymes for more than 1,500 organisms. 3) *BOCD* (BioCyc Open Compounds Database) is an open collection of chemical compound data from the BioCyc databases. BOCD includes metabolites, enzyme activators, inhibitors, and cofactors. Tier 2: 20 Databases, which were computationally generated and have undergone moderate curation. Tier 3: 349 Databases, which were also computationally generated, but have undergone no curation. Scientists can use the BioCyc Web site to visualize individual metabolic pathways or to view the complete metabolic map of an organism. The latter diagram can be used to analyze gene expression, proteomics, or metabolomics data, such as to produce animated views of time-course gene-expression experiments. The BioCyc Web site also provides genome browsing capabilities, and for the *EcoCyc* databases in particular, provides extensive information about transcriptional mechanisms of gene regulation.

The numerical database DETHERM provides thermophysical property data, which are indispensable for construction and design of chemical apparatus, plants and processes. DETHERM contains literature values, together with bibliographical information, descriptors and abstracts. The following properties for pure compounds and for mixtures are stored: 1) phase equilibrium data, 2) vapor pressures and critical data, 3) thermodynamic properties, 4) transport properties, 5) surface tensions, 6) electrolyte data.

The CRC Handbook of Chemistry and Physics (HBCP), updated annualy, provides broad coverage of all types of physical science data commonly encountered by scientists and engineers. It consists of tables of data and current international recommendations on nomenclature, symbols and units. A new series highlights the achievements of some of the major historical figures in chemistry and physics.

The Handbook of Heterogeneous Catalysis provides around 200 expert articles covering all aspects of the subject, from the physico-chemical fundamentals to large-scale industrial applications. It is based on the 2nd revised edition (2008), edited by Gerhard Ertl, Helmut Knözinger, Ferdi Schüth and Jens Weitkamp.

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 SpringerLink platform provides MPG staff with access to a huge collection of English and German eBooks from 2005 onwards, as well as the English and the German collection of the Springer Book Archive (1842-2004). In addition, the content of selected book series is available. Includes major reference works and dictionaries. Max Planck researchers who publish a monograph or edited volume with Springer Nature as an Open Access eBook receive a discount on the standard Book Publishing Charge. MPDL covers the costs remaining on a pro rata basis. Further details are available on the MPDL website.

Ullmann's Encyclopedia of Industrial Chemistry covers the science and technology of all areas of industrial chemistry. For each chemical substance, information on physical and chemical properties, production, applications, economic data, toxicology and occupational health is given.

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.

Zenodo is an open data repository, developed and operated by CERN. It is an catch-all repository, that welcomes research from all over the world, and from every discipline. Zenodo does not impose any requirements on format, size, access restrictions or licence. A digital object identifier (DOI) is automatically assigned to all Zenodo files and it is integrated into reporting for research funded by the European Commission.