Local versus Hyperspherical Modes of Formaldehyde I. Model Hamiltonian and Decay of the CH₂‐Fragment

Abstract

Abstract Highly vibrationally exited, near degenerate stretches of the CH 2 ‐fragment of formaldehyde yield rapid local versus slow hyperspherical decay. The dissociations are simulated using Fast‐Fourier‐Transform (FFT) time propagations of resonance wave packets on three model potentials. The time evolution allows to select an instructive model Hamiltonian for H 2 CO which describes normal modes as well as highly excited H 2 C stretches coupled to cold CO bonds.