Thermochemistry of calcium-containing molecules: An examination of the performance of high-level theoretical procedures

Leo Radom, Michael B. Sullivan, Naomi L. Haworth, Angela K. Wilson, Larry A. Curtiss, and Jan ML Martin

Contribution from School of Chemistry, University of Sydney, Building F11, Sydney, NSW, 2006, Australia, Research School of Chemistry, Australian National University, Canberra, ACT 0200, Australia, Department of Chemistry, University of North Texas, Box 305070, Denton, TX 76203-5070, Materials Science and Chemistry Divisions, Argonne National Laboratory, 9700 S. Cass Ave., Argonne, IL 60439, Department of Organic Chemistry, The Weizmann Institute of Science, Rehovot, 76100, Israel

Presented: 25 August 2004

ABSTRACT:

he calculation of reliable thermochemistry has become almost a routine task for many molecules, through the use of techniques such as the Gn procedures of Curtiss, Raghavachari and Pople, the CBS procedures of Petersson, and the Wn procedures of Martin. However, in recent studies of alkali and alkaline earth oxides and hydroxides, we found that the application of these methods in their standard formulations can sometimes lead to errors greater than 100 kJ/mol. Special modifications need to be introduced to avoid such errors. In this presentation, I will discuss our most recent work on the topic, focusing particularly on calcium-containing molecules.