Why it is sometimes difficult to determine the accurate position of a hydrogen atom by the semiexperimental method : structure of molecules containing the OH or the CH3 group

© 2014 Wiley Periodicals, Inc.

Bibliographische Detailangaben
Veröffentlicht in:Journal of computational chemistry. - 1984. - 35(2014), 32 vom: 15. Dez., Seite 2333-42
1. Verfasser: Vogt, Natalja (VerfasserIn)
Weitere Verfasser: Demaison, Jean, Vogt, Jürgen, Rudolph, Heinz Dieter
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2014
Zugriff auf das übergeordnete Werk:Journal of computational chemistry
Schlagworte:Journal Article ab initio structures coordinates of hydrogen atoms dimethyl ether ethanol glycolaldehyde hydroxyboranes propanal semiexperimental equilibrium structures of ethenol vibration-rotation corrections
Beschreibung
Zusammenfassung:© 2014 Wiley Periodicals, Inc.
The semiexperimental (SE) technique, whereby equilibrium rotational constants are derived from experimental ground-state rotational constants and corrections based on an ab initio cubic force field, has the reputation to be one of the most accurate methods to determine an equilibrium structure ( reSE). However, in some cases, it cannot determine accurately the position of the hydrogen. To investigate the origins of this difficulty, the SE structures of several molecules containing either the OH or the CH3 group are determined and compared to their best ab initio counterparts. It appears that an important factor is the accuracy of the geometry used to calculate the force field, in particular when the least-squares system is not well conditioned. In this case, the mixed regression method is often an easy way to circumvent this difficulty
Beschreibung:Date Completed 19.05.2015
Date Revised 10.11.2014
published: Print-Electronic
Citation Status PubMed-not-MEDLINE
ISSN:1096-987X
DOI:10.1002/jcc.23758