|Science.gov searches over 42 databases and over 2000 selected websites, offering 200 million pages of authoritative U.S. Government science information.
|The U.S. Department of Energy Office of Science and Technical Information portal searches 3+ million Department of Energy research results.
|Use the DOE Data Explorer to discover science, technology, and engineering data collections from the US Department of Energy.
ChemIDplus is a free, web search system that provides access to the structure and nomenclature authority files used for the identification of chemical substances cited in NLM databases, including the TOXNET system. ChemIDplus also has structure searching and direct links to resources at NLM, federal agencies, U.S states, and scientific sites. The database contains more than 400,000 chemical records, of which over 300,000 include chemical structures.
|A wealth of chemical information can be found at The National Institute of Standards and Technology website (NIST):
|The Technical Report Archive and Image Library ("TRAIL") is a project to digitize, archive, and provide persistent and unrestricted access to federal technical reports issued prior to 1975.
|PubMed comprises more than 19 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.
The National Institutes of Health (NIH) provide:
|Science nation is the "online magazine that's all about science for the people."
Supplemental Material for the Journal of Molecular Spectroscopy
|The Sheffield Chemdex-"the directory of chemistry on the WWW since 1993." Includes: WebElements (Interactive Periodic Table), The Orbitron: a gallery of atomic orbitals and molecular orbitals, and lots more.
|ChemSpider is a free chemical structure database providing fast text and structure search access to over 34 million structures from hundreds of data sources.
|IUPAC (The International Union of Pure and Applied Chemistry)
|IUPAC Gold Book (Compendium of Chemical Terminology)
|The Cambridge Crystallographic Data Centre (CCDC) is a non-profit organisation whose primary role is the compilation and maintenance of the Cambridge Structural Database, a database of small molecule crystal structures.
|MERLOT is a curated collection of free and open online teaching, learning, and faculty development services contributed and used by an international education community.
The U. of Wisconsin's Ebling Library provides up-to-date, user-friendly information on Federal Agency Public Access Compliance (arising from US OSTP Memo of February 2013 which requires open access publishing of research funded by US Gov agencies).