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Updated: Jun 8, 2026

Spatial Separation of Molecular Conformers and Clusters
Published on: January 9, 2014
An "adiabatic-hindered-rotor" treatment allows para-H(2) to be treated as if it were spherical
Hui Li1, Pierre-Nicholas Roy, Robert J Le Roy
1Institute of Theoretical Chemistry, State Key Laboratory of Theoretical and Computational Chemistry, Jilin University, 2519 Jiefang Road, Changchun 130023, People's Republic of China.
Abstract:
In para-H(2)-{molecule} interactions, the common assumption that para-H(2) may be treated as a spherical particle is often substantially in error. For example, quantum mechanical eigenvalues on a full four-dimensional (4D) potential energy surface for para H(2)-{linear molecule} species often differ substantially from those calculated from the corresponding two-dimensional (2D) surface obtained by performing a simple spherical average over the relative orientations of the H(2) moiety. However, use of an "adiabatic-hindered-rotor" approximation can yield an effective 2D surface whose spectroscopic properties are an order of magnitude closer to those yielded by a full 4D treatment.
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