Revision of several "key" thermochemical species from the NBS Tables using the Active Thermochemical Tables approach: A NIST-Argonne pilot project

PHYS 461

Abel Fernandez1, Branko Ruscic, ruscic@anl.gov1, Donald G. Archer2, Robert D. Chirico2, Michael Frenkel, frenkel@boulder.nist.gov2, and Joseph W. Magee2. (1) Chemistry Division, Argonne National Laboratory, Argonne, IL 60439, (2) Physical and Chemical Properties Division, National Institute of Standards and Technology, Gaithersburg, MD 20899
The popular NBS Tables of Chemical Thermodynamic Properties are an extremely valuable asset that has not been revised nor updated since its publication in 1982. An obvious barrier to revising a critical evaluation of thermochemical data is the immense effort that is entailed in such undertaking. With the appearance of Active Thermochemical Tables (ATcT), a new possibility for revising the NBS Tables has emerged, which is currently being addressed by a joint project undertaken by NIST and Argonne National Laboratory. For the pilot stage of this project, a target list of about two dozen “key” thermochemical species has been developed. The revision process involves the construction of the related portions of the Thermochemical Network (TN) Graph that defines the thermochemical properties of the target species through the inherent thermochemical interdependencies. The process makes use of the extensive archives of information that were utilized and critically evaluated during the construction of the original NBS Tables, further augmented by introducing all available thermochemically-relevant determinations that appeared since. The project leverages from the ability of ATcT to simultaneously evaluate massive amounts of interdependent information, as well as from the ATcT capability to accept incremental updates to the TN Graph and painlessly propagate the new knowledge through all affected values. The initial thermochemical results of the pilot project, as well as the new insights that allow the definition of the needed infrastructure that will automate significant aspects of the revision process are discussed.

Poster Session
7:30 PM-10:00 PM, Wednesday, 13 September 2006 Moscone Center -- Hall D, Poster

Division of Physical Chemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006