Systematic Investigation of the Reliability of the Frozen Nuclei Approximation for Short-Pulse Excitation: The Example of HCCI

Dongming Jia; Yonggang Yang

doi:10.3389/fchem.2022.857348

Systematic Investigation of the Reliability of the Frozen Nuclei Approximation for Short-Pulse Excitation: The Example of HCCI

Front Chem. 2022 Mar 16:10:857348. doi: 10.3389/fchem.2022.857348. eCollection 2022.

Authors

Dongming Jia¹, Yonggang Yang^{2

3}

Affiliations

¹ MOE Key Laboratory for Non-equilibrium Synthesis and Modulation of Condensed Matter, School of Physics, Xi'an Jiaotong University, Xi'an, China.
² State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University, Taiyuan, China.
³ Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, China.

Abstract

In this work we quantitatively study the reliability of the frozen nuclei approximation for ultrafast dynamics. Specifically we study laser excitation of HCCI⁺ from its ground state to the first electronically excited state. The population of the first excited state is obtained by both the frozen nuclei approximation and by multidimensional nuclear dynamics. Detailed comparison of the results by the two methods are performed to provide quantitative criteria for the reliability of the frozen nuclei approximation for this system.

Keywords: electronic excitation; frozen nuclei approximation; nuclear quantum dynamics; population transfer; ultrashort laser pulses.