National Institute of Standards and Technology WebBook (Popularity: ): Thermochemical data for over 6000 organic and small inorganic compounds. Reaction thermochemistry data for over 9000 reactions. IR spectra for over 8700 compounds. Mass spectra for over 12,000 compounds. UV/Vis ... Surface Tension Data (Popularity: ): Surface tension values of some common test liquids for surface energy analysis. Theoprax-Research (Popularity: ): Optimising reactions using pH spectrum, including research report and customer pH-spectra database from Katerini, Greece.