Quantum Dynamics of Linear Triatomic Reactions

Abstract

Publisher Summary In the dynamical context a linear triatomic system presents an ideally pure model of interaction and interconversion between the translational and vibrational motions during a chemical process. Being an excellent nontrivial test for a mathematical technique aimed at solving dynamical problems, it is also sufficiently realistic to be considered as a source of useful and visual physical concepts. A general qualitative approach in chemical dynamics is based on a fruitful intuitive idea of a reaction coordinate. Its mathematical formulation introduces special curvilinear coordinates describing a continuous transformation of a chemical system from an initial to a final state. An exact version of this theory becomes considerably complicated in the case of a large curvature of the reaction coordinate. If this complication is disregarded, the dynamical treatment of polyatomic systems may be reduced, similar to the triatomic case, to a study of interactions between the translational motion along a reaction coordinate and transversal vibrational motions. When vibrational amplitudes are small, one neglects coupling of the above-mentioned motions with the overall rotation of a system. This simplification is well known in the theory of molecular vibrations and is equally valid for treating a one-parameter evolution of a system of harmonic oscillators, which is a natural description of the motion of a polyatomic system along a reaction coordinate.