Quantum calculation of the vibrational energy level structure of N2O based on ab initio potential surface

A quantum calculation of 1647 bound states of N2O, up to near the dissociation threshold, is presented. The potential energy surface derived from ab initio calculations was employed. In an attempt to characterize the dynamics at various energy ranges, we analyzed the vibrational energy level structure using two statistical methods. For probing the short-range correlation of the spectrum, level spacing statistics were applied, which showed that the vibrational states consist of three distinct energy ranges characterized by regular, intermediate and irregular motion. The Δ̄3 statistics were also employed for probing the long-range correlation in the whole spectrum and showed that N2O cannot be identified simply as a regular or irregular system.