Journal ArticleDOI
Anharmonic force constant calculations
A.R. Hoy,Ian Mills,G. Strey +2 more
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The relationship of the anharmonic force constants in curvilinear internal coordinates to the observed vibration-rotation spectrum of a molecule is reviewed in this paper, where a simplified method of setting up the required non-linear coordinate transformations is described: this makes use of an L tensor, which is a straightforward generalization of the L matrix used in the customary description of harmonic force constant calculations.Abstract:
The relationship of the anharmonic force constants in curvilinear internal coordinates to the observed vibration-rotation spectrum of a molecule is reviewed. A simplified method of setting up the required non-linear coordinate transformations is described: this makes use of an L tensor, which is a straightforward generalization of the L matrix used in the customary description of harmonic force constant calculations. General formulae for the L tensor elements, in terms of the familiar L matrix elements, are presented. The use of non-linear symmetry coordinates and redundancies are described. Sample calculations on the water and ammonia molecules are reported.read more
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Solution of the Schrödinger equation by a spectral method II: Vibrational energy levels of triatomic molecules
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TL;DR: The spectral method as discussed by the authors utilizes numerical solutions to the time-dependent Schrodinger equation to generate the energy eigenvalues and eigenfunctions of the timeindependent Schröter equation.
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A practical method for the use of curvilinear coordinates in calculations of normal-mode-projected displacements and Duschinsky rotation matrices for large molecules
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An improved potential for non-rigid water molecules in the liquid phase
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References
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Simplification of the molecular vibration-rotation hamiltonian
TL;DR: In this paper, the Darling-Dennison vibration-rotation hamiltonian for a non-linear molecule is rearranged to the form: the order of the factors in the first term is immaterial, on account of the relation.