The NIST Chemistry WebBook, sixth edition contains thermochemical data for over 6500 organic and small inorganic compounds, reaction thermochemistry data for over 9800 reactions, IR spectra for over 8700 compounds, mass spectra for over 12,600 compounds, UV/Vis spectra for over 400 compounds, electronic / vibrational spectra for over 4100 compounds, constants of diatomic molecules (spectroscopic data) for over 600 compounds, ion energetics data for over 16,000 compounds, and thermophysical property data for 33 fluids. There are many avenues for searching the database.

• NIST Chemistry WebBook