Statistical analysis of the dependence of correlation energy and zero point energy on the nuclear frame and number of electrons in molecular systems

Abstract

Recently, we have developed twin methods, REBECEP [S. Kristyan, A. Ruzsinszky, G.I. Csonka, Theor. Chem. Acc. 106 (2001) 319] [14] for correlation and basis set error calculation and REZEP for zero point energy estimation [A. Ruzsinszky, S. Kristyán, J. Margitfalvi, G.I. Csonka, J. Phys. Chem. A 107 (2003) 1833] [6], both from atomic partial charges. We used databases of G2 and G3/99 total energies, as well as scaled HF-SCF/6-31G(d) zero point energies, both with certain atomic partial charges of more than 100 closed shell neutral molecules containing H, C, N, O, and F atoms. Our method showed near 1.0 kcal/mol average absolute deviation from the experimental results with much less computational time and disc space demand. In this respect, we carry out some statistical analysis to establish a plausible physical background for the parameters of these two empirical methods. The dependency, indicated in the title, is very interesting in the general theory of correlation energy and zero point energy as well. © 2004 Elsevier B.V. All rights reserved.