Vibrational energy levels of the S₀ and S₁ states of formaldehyde using an accurate ab initio based global diabatic potential energy matrix

Abstract

Low-lying vibrational energy levels of both the ground (S₀) and first excited singlet (S₁) states of formaldehyde have been determined using an exact kinetic energy operator and adiabatic potential energy surfaces derived from a recently developed full-dimensional global diabatic potential energy matrix (DPEM) based on a neural network representation of high level ab initio data. The agreement with available experimental band origins provides strong evidence in support of the accuracy of the DPEM, which can be used in the future for understanding the internal conversion of H₂CO(S₁) and the subsequent roaming dynamics on its S₀ state.

GRAPHICAL ABSTRACT

KEYWORDS:

• Vibrational spectroscopy
• potential energy surface
• formaldehyde

Acknowledgements

CX was supported by National Natural Science Foundation of China (Grant No. 22073073). The JHU and UNM teams were supported by US Department of Energy (Grant. No. DE-SC0015997). We also thank NERSC for computational resources.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by Basic Energy Sciences [grant number DE-SC0015997] and National Natural Science Foundation of China [grant number 22073073].