On the application of Canonical Perturbation Theory up to the dissociation threshold

TL;DR

This paper demonstrates that Canonical Perturbation Theory can accurately approximate the Hamiltonian of a coupled Morse oscillator system up to the dissociation threshold, with comparisons between quantum and classical results.

Contribution

It shows the effectiveness of Canonical Perturbation Theory in modeling a complex coupled system near dissociation, extending its applicability.

Findings

Canonical Perturbation Theory provides a good approximation up to the dissociation threshold.

Quantum and classical results are consistent in the studied model.

The method offers a precise, though not exact, Hamiltonian approximation.

Abstract

We investigate a model system consisting of a Morse oscillator strongly coupled to a doubly-degenerate bending degree of freedom and show that Canonical Perturbation Theory is able to provide a fairly precise, though not exact, approximation of the Hamiltonian up to the dissociation threshold. Quantum mechanical results and classical ones are discussed in this Letter.