New Ab Initio Potential Energy Surface and Quantum Product-State Resolved Reaction Dynamics Investigation for the H +...

Area of Science:

• Chemical Dynamics
• Quantum Chemistry
• Spectroscopy

Background:

• The H + F2 reaction is crucial for theoretical chemistry and chemical laser applications.
• Accurate potential energy surfaces (PES) are essential for understanding reaction dynamics.

Purpose of the Study:

• To develop a highly accurate PES for the H + F2 reaction.
• To perform a product-state resolved reaction dynamics study for H + F2 (v0=0, j0=0,1,2) → HF + F.
• To investigate the reaction within a collision energy range of [0.0, 1.0] eV.

Main Methods:

• Utilized the permutation invariant polynomial neural network method to construct the HF2 PES.
• Employed the time-dependent wave packet method for reaction dynamics.
• Calculated thousands of energy points using the MRCI-F12+Q method with AVTZ basis sets.

Main Results:

• Found that reactant F2 rotational excitation has minimal impact on the reaction.
• Observed significant vibrational population inversion in HF products, favoring v'=4-7 states.
• Noted that lower collision energies favor highly excited HF rotational states, while higher energies yield Gaussian distributions.

Conclusions:

• The H + F2 reaction serves as an excellent prototype for chemical lasers, similar to H2 + F.
• Calculated reaction rate constants show good agreement with experimental data, with slight underestimation.
• The study provides valuable insights into the dynamics of this important chemical reaction.