ISSN:
0192-8651
Keywords:
Computational Chemistry and Molecular Modeling
;
Biochemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Computer Science
Notes:
The geometries and force fields of the different conformers of five alkenes and five chloroalkanes (17 conformers in total) were calculated in the MINDO/3 approximation and compared with the corresponding experimental values. The direct use of geometrical or vibrational parameters derived from MINDO/3 either as starting values or as a source of constraints in the analysis of gas-phase electron diffraction data presents great risks. After a scaling procedure in which the calculated values are fitted to the experimental ones for a small number of compounds, scale factors can be obtained which, with due caution, are transferable to other molecules in the same class. Scaled MINDO/3 produces geometries and force fields that fit to experiment considerably better than their unscaled counterparts. However, scaled MINDO/3 does not produce better results than molecular mechanics. Calculated energy differences between rotamers are generally too high.
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jcc.540020112
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