Ab initio molecular dynamics studies on the ground singlet potential energy surface of the tetraoxygen molecule, O 4

Abstract

We study the finite temperature dynamical process followed by the D 2d singlet ground state of tetraoxygen, O 4. Born–Oppenheimer ab initio molecular dynamics (AIMD) simulations are done at near-room temperature and at 700 K using a calibrated DFT-based electronic structure description. The vibrational spectra are reported and the lowest vibrational modes are identified, which correlate well with ab initio static predictions. The largest non-harmonic contributions on the spectra are found for the modes involving ν 5(B 1) and ν 6(A 1) quanta. The relative vibrational peak intensities provide valuable information for the identification of this as yet undetected stable polyoxygen species.