Physics

The SAO/NASA Astrophysics Data System (ADS) is a digital library portal for researchers in astronomy and physics, operated by the Smithsonian Astrophysical Observatory (SAO) under a NASA grant.

AstroWeb is a collection of pointers to astronomically relevant Internet resources. Discontinued on 10 July 2010.

The European Southern Observatory ESO is the leading astronomical organisation in Europe and the most scientifically fruitful astronomical research facility in the world.

SciTech Connect is a portal to free, publicly-available DOE-sponsored R&D results including technical reports, bibliographic citations, journal articles, conference papers, books, multimedia, software, and data information, and was developed by the U.S. Department of Energy

INSPIRE is a high-energy physics database developed by CERN, DESY, Fermilab and SLAC.

American Chemical Society

An interface to a crystal structure database that includes every structure published in the American Mineralogist, The Canadian Mineralogist, European Journal of Mineralogy and Physics and Chemistry of Minerals, as well as selected datasets from other journals.

Open-access collection of crystal structures of organic, inorganic, metal-organic compounds and minerals, excluding biopolymers.