Quantum rotational scattering of H₂ and its isotopologues with He

ABSTRACT

Quantum close-coupling computations of the rotational quenching of H₂ and its isotopologues due to He impact are performed using a highly accurate potential energy surface. State-to-state cross sections are obtained in a wide range of collision energies between 10⁻⁵ cm⁻¹ and 10⁴ cm⁻¹, and the theoretical rate coefficients are reported for temperatures ranging from 10⁻⁴ K to 3000 K. Compared with previous studies, the well depth of the potential adopted in this study is larger, leading to stronger resonance effects in the cross sections of He-HD. The accurate potential was employed to investigate the isotope effects of H₂ in detail. The cross-section resonances shift towards lower collision energies and become stronger with increasing reduced mass. The calculated cross sections and rate coefficients of H₂ and its isotopic variants in collisions with He are provided to study the energy transfer in these systems.

KEYWORDS:

• Molecular data
• rotational quenching
• cross section
• rate coefficient

Acknowledgment

This work was supported by the National Natural Science Foundation of China (Grant No. 11374045). We thank Benhui Yang for useful discussions.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

National Natural Science Foundation of China [grant number 11374045].