Interaction-Asymptotic Region Decomposition Method for a Triatomic Reactive Scattering with Symmetry Adoption

Area of Science:

• Quantum chemistry
• Chemical physics
• Theoretical chemistry

Background:

• Solving the coordinate problem in quantum wave packet calculations is computationally intensive.
• Triatomic reactive scattering processes require efficient methods for state-resolved calculations.

Purpose of the Study:

• To propose and validate the interaction-asymptotic region decomposition (IARD) method for general triatomic reactive scattering.
• To explore the use of symmetry in reducing computational costs for these calculations.

Main Methods:

• The IARD method uses Jacobi coordinates for asymptotic regions and hyperspherical coordinates for the interaction region.
• Symmetry properties of triatomic reactions (A + B2) are exploited to reduce the number of channels and spherical harmonics considered.
• The method's efficiency is demonstrated through calculations of product state-resolved reaction probabilities.

Main Results:

• The IARD method with symmetry adoption significantly reduces computational effort.
• Accurate reaction probabilities were calculated for ultracold collisions, including 16O + 36O2, 18O + 32O2, F + H2, and D+ + H2.
• Results were compared favorably with established methods like the ABC code.

Conclusions:

• The IARD method provides an efficient approach for state-resolved calculations in triatomic reactions.
• Incorporating symmetry is crucial for optimizing computational performance in quantum scattering calculations.
• This method is particularly advantageous for ultracold collision regimes.