Chemistry » Physical

Science, Chemistry, Physical, Databases - Quantum Chemistry Literature DataBase. A literature database on ab initio MO calculations published in major journals of Chemistry, Physics and Computer Science since 1978.

http://qcldb2.ims.ac.jp/

National Institute of Standards and Technology WebBook

NIST site provides chemical and physical property data on over 40,000 compounds.

https://webbook.nist.gov/