Globally Accurate Potential Energy Surface for BH₂⁺2(1³A') Using the Switching Function Formalism

Area of Science:

• Theoretical Chemistry
• Quantum Chemistry
• Chemical Physics

Background:

• Accurate potential energy surfaces (PES) are essential for understanding chemical reaction dynamics.
• Previous theoretical studies on the BH2+ system lacked a globally accurate PES.

Purpose of the Study:

• To compute an exact three-dimensional potential energy surface for the ground-state BH2+.
• To develop a switching function for reliable dissociation limits.
• To calculate integral cross sections for the B+ + H2 reaction.

Main Methods:

• *Ab initio* energy points calculated using aug-cc-pV(Q,5)Z basis sets at the multireference configuration interaction level.
• Extrapolation to the complete basis set limit.
• Quasi-classical trajectory method for reaction cross-section calculations.

Main Results:

• A new, accurate global potential energy surface for ground-state BH2+ was obtained.
• A switching function was successfully developed to model electronic state transitions.
• Integral cross sections for the B+ + H2 reaction were calculated, supporting the PES reliability.

Conclusions:

• The developed potential energy surface is reliable and accurately represents the BH2+ system.
• The calculated cross sections provide validation for the new PES.
• This work advances the theoretical understanding of ion-molecule reactions involving boron.