STEM Data Repositories and Data Sets

PubChem is the world's largest collection of freely accessible chemical information. Search chemicals by name, molecular formula, structure, and other identifiers. Find chemical and physical properties, biological activities, safety and toxicity information, patents, literature citations and more.

Royal Society of Chemistry. Open access, fast text and structure search access to over 28 million chemical structures from a variety of data sources.

Open access database of chemicals including 45,000 synthesis references and physical properties on 40,000 compounds.

The Crystallography Database is an open-access collection of crystal structures of organic, inorganic, metal-organic compounds and minerals, excluding biopolymers.

Open access database of inorganic compounds predicted by various crystallography programs.