Torsional Angle Definitions and Linear and Quadratic Force Field Variations Along the Torsinal Coordinate for CH 3OH and CH3CHO

Published

January 1, 2002

Author(s)

L H. Xu, R M. Lees, M A. Mekhtiev, Jon T. Hougen

Abstract

This paper concerns itself primarily with three questions: (i) What is the range of commonly used definitions for the internal rotation angle, and how do variations within this range affect intercomparisons among results from various laboratories? (ii) Do projected force constant variations with internal rotation angle delivered by present commercial ab initio packages have sufficient precision to allow meaningful extraction of higher order torsion-rotation interaction terms? (iii) What fraction of the extensive chemical reaction dynamics literature can be easily adapted for use in high-resolution spectroscopic studies of small-amplitude vibrations in methyl top internal rotor molecules? Possible answers to these questions are discussed both from an algebraic and from a numerical computation point of view.

Citation

Journal of Molecular Spectroscopy

Volume

214

Pub Type

Journals

Keywords

ab initio, internal rotation, intrinsic reaction coordinate, large-amplitude motion, minimum energy path, small-amplitude vibrations

Citation

Xu, L. , Lees, R. , Mekhtiev, M. and Hougen, J. (2002), Torsional Angle Definitions and Linear and Quadratic Force Field Variations Along the Torsinal Coordinate for CH ₃OH and CH₃CHO, Journal of Molecular Spectroscopy (Accessed October 14, 2025)