The NIST WebBook: NIST Chemical Reference Data for Industry

W.G. Mallard, P.J. Linstrom, J.F. Liebman (Univ. of Maryland, Baltimore County), and P.J. Christian

Objective: To provide Internet access to a complete set of chemical data with a common interface that is both easy to use and easily expanded.

Problem: There is an enormous amount of organic thermochemical data (heats of formation, entropies, heat capacities, heats of reaction) that are largely unknown to the technical community. One part of this project is to find and evaluate those data. In addition, there is a need to make available ancillary thermochemical data such as phase-change enthalpies. Data on infrared, ultraviolet, and mass spectra are often difficult to find. For all of these data, it is essential that tools be developed to provide easy access.

Approach: It is clear that the World Wide Web has dramatically changed the way that scientific information is communicated. The use of the Web as a publishing medium and as a resource for communication has been growing rapidly. What has not followed is the development of reliable data resources for the Web. The WebBook is an effort to correct this. The WebBook provides a fast and direct source of data available at all times. The initial efforts have been tied to an approach based on compounds rather than properties. All the data on benzene, for example, are gathered together, rather than all the data on heat of combustion. While the major thrust of the WebBook is to supply data from NIST evaluations, the role of the WebBook in providing a resource for chemical data from all sources will expand. In parallel with the efforts to gather and evaluate data, another major part of this project is aimed at providing the mechanisms needed to make these and other NIST chemical reference data available on the Internet. These efforts are part of NIST’s program on Systems Integration for Manufacturing Applications (SIMA).

Results and Future Plans: During FY99 the fifth edition of the NIST Chemistry WebBook* was released. The total number of compounds for which data are provided has steadily increased and in the fifth edition, data for more than 31,800 compounds are available. As with every previous release, new data types were added; specifically, Henry’s law data and UV/Visible spectral data. In addition, new data on critical constants, vapor pressure, and ion energetics were added, as well as significant increases in many of the thermodynamic data types. A new tool for substructure searching using chemical structures drawn by the user has been added. The number and variety of users—in industry, government, and academia—are a clear indication of the need for this type of service. Between 6000 and 12000 users per week use the Chemistry WebBook, an increase of about 25% from last year; and the fraction of returning users is between 45% to 55%. The WebBook is also a tool to aid future evaluation projects both at NIST and in collaboration with others. The goal of this project is to have a single point of entry for access to all chemical data at NIST. It is anticipated that during FY 2000, there will be two releases of the NIST WebBook. Additional data as well as new searching software will be included.

*http://WebBook.nist.gov

Publications:

Linstrom, P.J. and Mallard, W.G., "The NIST WebBook: A Tool for Chemical Data Access on the Internet," Proceedings of the 10^th International Chemical Information Conference and Exhibition, Nimes, France, October 18-21, 1998.