Abstract
Absolute intensities are calculated in the harmonic approximation for the IR spectrum of 18 hydrocarbons, oxygen- and nitrogen-containing organic compounds. The quantum chemical calculation is carried out in the 6-311G(3df,3pd) basis set. The calculated data are compared to the experimental values of absolute absorption intensities. It is found that calculations in the HF approximation substantially overestimate (on average by 87%) the integral absolute intensity of fundamental vibrations in the 575–4000 cm−1 range. Most part of this overestimation falls on the stretching vibrations with large amplitudes (C-H and C=O bonds). When the MP2 method is used without electron correlation treatment, this overestimation decreases to 22% and becomes more uniform in the whole spectral region.
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References
R. P. Feinman, Phys. Rev., 56, 340 (1939).
Site of the US Institute of Standards and Technology http://webbook.nist.gov/chemistry/
M. W. Schmidt, K. K. Baldridge, J. A. Boatz, et al., J. Comput. Chem., 14, 1347 (1993).
M. A. Elyashevich, Atomic and Molecular Spectroscopy [in Russian], GIFML, Moscow (1962).
B. F. Myasoedov, L. A. Gribov, A. I. Pavlyuchko, et al., J. Struct. Chem., 47, No. 3, 434–441 (2006).
L. A. Gribov and A. I. Pavlyuchko, Variation Methods to Solve Anharmonic Problems in the Theory of Molecular Vibrational Spectra [in Russian], Nauka, Moscow (1998).
A. I. Pavlyuchko and L. A. Gribov, J. Struct. Chem., 51, No. 3, 444–452 (2010).
A. I. Pavlyuchko, E. V. Vasiliev, and L. A. Gribov, Zh. Anal. Khim., 65, No. 12, 1264 (2010).
A. I. Pavlyuchko, E. V. Vasiliev, and L. A. Gribov, J. Struct. Chem., 51, No. 6, 1045–1051 (2010).
A. I. Pavlyuchko, E. V. Vasiliev, and L. A. Gribov, Zh. Anal. Khim., 66, No. 6, 589 (2011).
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Original Russian Text Copyright © 2012 by A. I. Pavlyuchko, E. V. Vasiliev, L. A. Gribov
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Translated from Zhurnal Strukturnoi Khimii, Vol. 53, No. 2, pp. 278–284, March–April, 2012.
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Pavlyuchko, A.I., Vasiliev, E.V. & Gribov, L.A. On the accuracy of ab initio calculations of absolute band intensities in the IR spectra of molecules. J Struct Chem 53, 276–282 (2012). https://doi.org/10.1134/S0022476612020102
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DOI: https://doi.org/10.1134/S0022476612020102