Rigid rotor state-to-state cross-sections and rates of the PH3 + H2 collision

Authors

Faouzi Najar
Ayda Badri
Herve Tajouo Tela
Steve Ndengué, Haverford CollegeFollow
Nicola Tasinato

Document Type

Journal Article

Role

Author

Journal Title

Physical Chemistry Chemical Physics

Volume

2025

Issue

27

First Page

19500

Last Page

19508

Publication Date

8-4-2025

Abstract

Accurate interpretation of observational astronomical data requires reliable collisional rate coefficients for inelasting scattering events between interstellar molecules and the abundant buffer species. A five-dimensional potential energy surface (PES) for the PH₃ ( ¹A₁) – H₂ (¹Σ⁺g) interaction was generated using the explicitly correlated CCSD(T)-F12 method in conjunction with the correlation-consistent triple-zeta aug-cc-pVTZ basis set, and averaged over H₂ orientations to yield a reduced three-dimensional surface. Inelastic rotational cross-sections for collisions between ortho and para-PH₃ with para-H₂ (J = 0) are calculated using the close-coupling quantum scattering method. After Boltzmann thermal averaging, the rate coefficients are evaluated for temperatures up to 100 K. Our results reveal substantial discrepancies between computed PH₃-para-H₂ collisional rates and scaled PH₃–He values, underlining the inadequacy of scaling approaches for reliable astrophysical modelling.

Repository Citation

Najar, F., et al. (2025). "Rigid rotor state-to-state cross-sections and rates of the PH3 + H2 collision." Physical Chemistry Chemical Physics, 2025(27):19500-19508. https://doi.org/10.1039/D5CP02236C