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New NIST 'Webbook' Offers Collection of Chemistry Data Online

Envisioned to replace bulky reference books and trips to research libraries, NIST’s new compilation of chemical and physical data, the NIST Chemistry WebBook, is now available on the Internet. This new electronic service, available at, will help scientists retrieve chemical and physical data collections in one convenient location on the World Wide Web.

NIST’s new Chemistry WebBook will provide access to the full array of chemical data distributed through NIST's Standard Reference Data Program. The current edition contains mass spectral data, thermochemical properties, infrared spectral data, heat of reaction data, vapor pressure data and ionization energies for thousands of chemical compounds.

Anyone with access to the World Wide Web can search for data on specific compounds in the NIST Chemistry WebBook based on name, chemical formula or Chemical Abstract Service registry number, molecular weight, ionization energy or proton affinity.

Computer users with web browsers supporting JAVA can select and enlarge small portions of wavelength or mass ranges on their video displays.

Using the NIST Chemistry WebBook, researchers will be able to find:

  • thermochemical data on more than 4,000 organic and small inorganic compounds including enthalpy of formation, enthalpy of combustion, heat capacity, entropy, phase transition enthalpies and temperatures, and vapor pressure;
  • heat of reaction data for more than 1,300 reactions;
  • IR spectra for more than 5,000 compounds;
  • mass spectra for more than 8,000 compounds;
  • ion energetics data for more than 12,000 compounds including ionization energy, appearance energy, proton affinity and gas basicity.

The NIST Chemistry WebBook also offers Internet users a glimpse of the more than 50 databases available from the NIST Standard Reference Data Program, which has been providing evaluated, high-quality data for a wide range of applications to industry, government and academic institutions for 30 years. Access to the NIST SRD collections in the WebBook is currently free, but NIST may charge for this service in the future.

The NIST Standard Reference Data Program provides well-documented numeric data to scientists and engineers for use in technical problem-solving, research and development. These recommended values are based on data that have been extracted from the world’s literature, assessed for reliability and then evaluated to select the preferred values. These data activities are conducted by scientists at NIST and in university data centers.

Information on NIST Standard Reference Data is available from the NIST Standard Reference Data Program, Bldg. 820, Rm. 113, Gaithersburg, Md. 20899-0001, (301) 975-2208, fax: (301) 926-0416, or .

As a non-regulatory agency of the Commerce Department’s Technology Administration, NIST promotes U.S. economic growth by working with industry to develop and apply technology, measurements and standards.

Released May 30, 1997, Updated November 27, 2017