CALCULATIONS OF EFFECTIVE CHARGES
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Date
1972
Journal Title
Journal ISSN
Volume Title
Publisher
Ohio State University
Abstract
Blanchette, Mast and $King^{1}$ have shown that characteristic ``effective charges’’ for the carbon and hydrogen atoms can be calculated for hydrocarbons simply from a knowledge of the intensity sum for 2 isotopic derivatives of any hydrocarbon. Since these ``effective charges’’ are independent of the normal coordinates, they are especially important in testing the quality of quantum-mechanical wavefunctions with respect to their ability to predict infrared intensities. Although the approximate quantum-mechanical wavefunctions generated by the CNDO technique are not expected to give the best possible predictions for these quantities, the general success of these wavefunctions in correlating infrared intensities $results^{2}$ has encouraged us to calculate effective charges from these wavefunctions. The results from these calculations indicate that the empirically discovered constancy of these parameters in hydrocarbons may indeed be justified by the calculated results. The calculated results provide some insight into the nature of these parameters. We are grateful to the National Science Foundation (Grant No. GP-17818) for support of this work.
Description
$^{1}$P. P. Blanchette, G. M. Mast and W. T. King, to be published in J. Chem. Phys. $^{2}$G. A. Segal and M. L. Klein, J. Chem. Phys., 47, 4236 (1967); I. W. Levin and T. P. Lewis, ibid., 52, 1608 (1970); see also D. C. McKean, R. E. Bruns, W. B. Person and G. A. Segal, ibid., 55 2890 (1971). R. Bruns and W. B. Person ibid., 55 5401 (1971)""
Author Institution: Department of Chemistry, University of Florida
Author Institution: Department of Chemistry, University of Florida