Full Q-space analysis of molecular dynamics effect on electron momentum profile of outer-valence orbitals of oxetane

• Published in: Chemical physics 2023-07, Vol.571, p.111922, Article 111922
• Main Authors: Liu, Tuo, Wang, Enliang, Tang, Yaguo, Shan, Xu, Chen, Xiangjun
• Format: Article
• Language: English
• Subjects: Electron momentum spectroscopy; Oxetane; Thermal sampling; Vibration effect
• ISSN: 0301-0104
• DOI: 10.1016/j.chemphys.2023.111922

The molecular dynamics effect on electron momentum profiles (EMPs) of outer-valence orbitals of oxetane was investigated theoretically by using the thermal sampling molecular dynamics (TSMD) method to prepare the initial condition of molecules at a certain temperature. A full Q-space sampling is achieved including both harmonic and anharmonic vibrations, particularly the ring-puckering vibration. The sampled conditions were testified by comparing the simulated electron binding spectrum with the photoelectron spectrum. The plane wave impulse approximation (PWIA) is adopted to calculate the EMPs. The results of outer valence orbitals of oxetane are compared with experiments adopting the asymmetric noncoplanar kinematics and theoretical results by ring-puckering model and the harmonic analytical quantum mechanical (HAQM) model. For 3b1 orbital, where the vibrational excitation and anharmonicity of ring-puckering mode cannot be ignored, the present model gives an improved description. For the other orbitals, the present results are similar to the predictions by the HAQM model. •The initial state vibration of the molecule is sampled by the thermal sampling molecular dynamics (TSMD) method which includes both the harmonic and anharmonic vibrations of the molecule.•The initial vibrational excitation can be considered by the Boltzmann distribution at a specific temperature.•A full Q-space analysis can be achieved by a large number of sampled molecular geometries.•The model was testified by comparing the simulated results with the experimental data both in the high-resolution photoelectron spectrum and in the EMPs together with the available theoretical results. For the HOMO of oxetane, the present model gives the best description.