PubChem
"[..] We collect information on chemical structures, identifiers, chemical and physical properties, biological activities, patents, health, safety, toxicity data, and many others."(About)
NDC: 431
ChemSpider
"A free chemical structure database providing fast text and structure search access to over 130 million structures from hundreds of data sources."(meta name="description")
NDC: 431
Welcome to ECS
"The Electrochemical Society is creating uninhibited availability of the science through open access and accelerating scientific discovery and innovation."(meta name="description")
NDC: 431