Where can I find spectral data for materials? The chemical library of ChemSpider has a dedicated section for spectra, but I haven't found any materials that have such data. Is there a (public) database of spectral data?
 A: If you are interested in molecules then
The nist webbook has a huge store of information ---- see
http://webbook.nist.gov     (NB no pay wall)
You can search pretty easily and get mass spectra, heats of formation and some information about IR and UV/Vis spectra as well
To quote from their front page there are....


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*Thermochemical data for over 7000 organic and small inorganic compounds:

*Reaction thermochemistry data for over 8000 reactions.

*IR spectra for over 16,000 compounds.

*Mass spectra for over 33,000 compounds.

*UV/Vis spectra for over 1600 compounds.

*Gas chromatography data for over 27,000 compounds.

*Electronic and vibrational spectra for over 5000 compounds.

*Constants of diatomic molecules (spectroscopic data) for over 600 compounds.

*Ion energetics data for over 16,000 compounds:


If you are interested in solid state materials then you may need to look elsewhere.... 
The way to use the NIST Chemistry Webbook is to put in the formula of the molecule you are interested in and then it will show you what resources are available for that molecule. Formulae can be enetered from this page
A: Some note-worthy index pages for spectal data:


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*XPS data for all elements: in a periodic table format

*Quantitative Infrared Database

*THz Spectral Database

*X-ray properties of elements (also in a periodic table format)

