Phenomenological characterization of the isomerization transition state of carbonyl sulfide

TL;DR

This paper investigates the isomerization transition state of carbonyl sulfide by modeling its bending motion with an effective Hamiltonian, improving a phenomenological formula to better estimate the energy barrier and capture anharmonicity effects.

Contribution

It introduces a new term to an existing phenomenological formula, enhancing the accuracy of transition state energy barrier estimation for quasilinear molecules.

Findings

Improved phenomenological formula for energy barrier estimation

Accurate description of critical phenomena in molecular bending spectra

Enhanced understanding of anharmonicity in isomerization transition states

Abstract

Signatures of excited-state quantum phase transitions in the bending degree of freedom of triatomic systems that undergo an isomerization reaction have been recently evinced. In this work, we study the carbonyl sulfide bending motion using an effective Hamiltonian within the two-dimensional limit of the vibron model framework, which has been shown to accurately describe critical phenomena in molecular bending spectra within experimental precision. To estimate the transition state energy barrier, we propose an improvement to a phenomenological formula proposed by Baraban et al.[1] , introducing a new term to capture the anharmonicity change that characterizes quasilinear molecules