Spectra and Spectral Data. NIST Chemistry WebBook Contains IR, mass, electronic/vibrational, and UV/VIS spectra as well as constants of diatomic molecules (spectroscopic data) and ion energetics data, etc., drawn from various evaluated sources. Properties of Organic Compounds Contains searchable spectral peak data (no charts) on about 29,000 important organic substances. The POC database is based on data currently collected for the CRC Handbook of Chemistry and Physics, as well as the old Atlas of spectral data and physical constants for organic compounds (1975). It contains references to the older Sadtler spectra collections if you need to get the graphical spectrum.
(ChemnetBase) Reaxys (Beilstein and Gmelin) The Beilstein and Gmelin files (now contained in the Reaxys system) include spectral data for organic and inorganic compounds respectively, excerpted from the journal literature. SciFinder (Registry) CAS has added experimental spectra for over 700,000 compounds in the Registry database. Sigma-Aldrich.com. Spectral Data and Spectroscopy Information - Chemistry Library - UW-Madison. Comprehensive Table of Spectroscopic Databases. CCCBDB Computational Chemistry Comparison and Benchmark Database.