Most free spectral libraries contain relatively few spectra compared to those available via subscription or purchase. This list is divided into two sections: the best starting places, and then some other useful sites. For more resources select from the menu to the left.
Start with these free sites:
- SDBS - Spectral Database System
- IR, 1H-NMR, 13C-NMR, mass, and ESR spectra of organics, searchable by name, formula, Registry Number, NMR shifts, and IR and MS peaks. (National Institute of Materials and Chemical Research, Japan)
- FT-IR/Raman and NMR spectra of most compounds in the catalog are available as PDF files. Search by catalog number, name, formula, CAS registry number.
- NIST Chemistry WebBook
- The WebBook contains thousands of 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.
...and these restricted to UT-Austin persons:
- Reaxys (Beilstein and Gmelin)
- The Beilstein and Gmelin files (contained in the Reaxys system) include spectral data for organic and inorganic compounds respectively, excerpted from the journal literature. Reaxys does not contain graphical spectra diagrams, and may only provide the pertinent literature reference. SeeLiterature Searching for more information.
- SciFinder (Registry)
- CAS has added experimental spectra for over 700,000 compounds in the Registry database. IR, MS and NMR spectra are from Wiley spectral databases and the Japanese SDBS database. In addition, CAS has added millions of predicted proton and 13C NMR spectra from ACD Labs and about 75,000 experimental 13C and 1H NMR spectra from BioRad-Sadtler.
- 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)
... and then some more specialized sources:
- Biological Magnetic Resonance Data Bank
- Quantitative data derived from NMR spectroscopic investigations of biological macromolecules. (Univ. of Wisconsin)
- Bio-Rad KnowItAll Academic Edition
- This free Windows software package allows you to draw structures, import spectra and perform IR and Raman functional group analysis, and generate reports. (It's not a spectral library though.)
- ChemExper Chemical Directory
- Contains IR spectra (via interactive applet) for various compounds. The directory can be searched by registry number, molecular formula, chemical name or synonyms in different languages as well as by physical and chemical characteristics and combinations of those data. May also be searched by substructure. The data are submitted from various sources and should not be considered critically evaluated.
- Combined Chemical Dictionary
- Database containing basic physical and spectral data (but not diagrams) and selected literature references for over 500,000 chemical substances and their derivatives. (CRC ChemnetBase)
- EPA/USAF Spectral Database
- Spectra and spectroscopic data of species of interest to the pollution monitoring and gas diagnostics community. Spectra files are in .spc format, requiring a special viewer such as ShowSPC.
- Mineral Spectroscopy Server
- Files of visible, Raman, and IR spectra of minerals, plus links to other collections. (Caltech)
- NIST Atomic Spectra Database
- "The Atomic Spectra Database (ASD) contains data for atom and ion transitions, and energy levels. Lines are included for the first 99 elements in the periodic table. The energy level tables also contain ionization limits. ASD contains data on about 950 spectra, with about 144,400 lines from 0.4 to 5,000,000 angstroms in wavelength, plus about 77,000 energy levels."
- NIST Handbook of Basic Atomic Spectroscopic Data
- "This handbook is designed to provide a selection of the most important and frequently used atomic spectroscopic data in an easily accessible format. The compilation includes data for the neutral and singly-ionized atoms of all elements hydrogen through einsteinium (Z = 1-99). The wavelengths, intensities, and spectrum assignments are given in a table for each element, and the data for the approximately 12,000 lines of all elements are also collected into a single table, sorted by wavelength (a "finding list")."
- NIST Molecular Spectra Databases
- "Three databases of diatomic, triatomic, and hydrocarbon molecules were originally published as spectral tables in the Journal of Physical and Chemical Reference Data. Each covers primarily the microwave region with some data for the radio frequency region. Rotational spectral lines for 121 diatomic molecules, 55 triatomic molecules, and 91 hydrocarbons have been tabulated. The isotopic molecular species, assigned quantum numbers, observed frequency, estimated measurement uncertainty, and reference are given for each transition."
- NIST X-Ray Photoelectron Spectroscopy Database 3.5
- The free version provides "access to the energies of many photoelectron and Auger-electron spectral lines. Resulting from a critical evaluation of the published literature, the database contains over 22,000 line positions, chemical shifts, doublet splittings, and energy separations of photoelectron and Auger-electron lines. A highly interactive program allows the user to search by element, line type, line energy, and many other variables. Users can easily identify unknown measured lines by matching to previous measurements."
- Raman Spectroscopic Library of Natural and Synthetic Pigments
- Raman spectra of 56 common pigments known to have been in use before 1850, arranged by color. (Univ. Coll. London)
- Romanian database of Raman spectroscopy
- Contains Raman and crystal data on a small number of mineral species.
- RRUFF (Raman Spectra of Minerals)
- "The RRUFF Project is creating a complete set of high quality spectral data from well characterized minerals and is developing the technology to share this information with the world. Our collected data provides a standard for mineralogists, geoscientists, gemologists and the general public for the identification of minerals both on earth and for planetary exploration." Entries include photos of the sample, collected data, and measured chemistry in addition to the locality and source. (Univ. of Arizona)