|
Tarasov Yu. I., Kochikov I. V., Spiridonov V. P., Kuramshina G. M., Saakjan A. S.
Scaling of Cubic
Force Constants in Electron Diffraction Structure Analysis with Application to
C4H4S as a Sample
Abstract
The
contributions of quantum chemical cubic constants of intramolecular force
fields calculated in different approximations are considered with respect to
analysis of theoretical electron diffraction intensities. Certain
underestimation of anharmonic effects was found in case of low-level calculations disregarding electron density correlations. The
analysis of anharmonic contributions to electron diffraction intensities
confirms that theoretical calculations are the satisfactory source of cubic
force constants. The empirical scaling of these constants partly allows to
overcome the difficulties associated with the limited accuracy of low level
theoretical calculations.
Copyright (C) Chemistry Dept., Moscow State University, 2002
|
|
