Subject: Comp. Chem. Comparison and Benchmark Database

From: Russ Johnson <[email-masked]>
Date: Wed, 19 Jan 2000 15:06:35 -0500

The computational chemistry group (http://www.nist.gov/compchem/) 
at NIST is developing several web databases to aid in the use of 
computational chemistry methods. 

The Computational Chemistry Comparison and Benchmark Database 
is accessible at:

http://srdata.nist.gov/cccbdb/

It is a collection of experimental and theoretical thermochemical 
properties for 580 neutral gas-phase species. The goal of the 
database/website is to provide a benchmark set of molecules 
and reactions for the evaluation of ab initio computational methods 
and to allow the comparison between different ab initio computational 
methods and experiment for the prediction of thermochemical properties.

The format of the site is to ask for the property of interest, then 
the molecule or molecules of interest, and then the level of theory. 
The experimental and computational data is available as is (heats 
of formation in kJ/mol, computed energies in hartrees, lists of 
vibrational frequencies) and the same data can also be used in 
comparisons. For example the reaction energy of a user-specified 
reaction can be listed for different levels of theory. 

So far the computational data is limited to 14 methods using the 
6-31G* basis set, AM1 and PM3 calculations, and some G2 calculations. 
The database is being expanded to include more than just the 6-31G* 
basis set, allowing access to the input and output files, converting 
the atomization energies and reaction energies to 298K (or any 
temperature), and filling in the many holes in both the computational 
and experimental data (there are 298K heats of formation for all 
species - eventually we hope to have experimental vibrational 
frequencies and structures for all species too.) 

Comments and questions can be sent to Russ Johnson 
([email-masked])