Analytic ab initio-based molecular interaction potential for the BrO⋅H2O complex

Area of Science:

• Atmospheric Chemistry
• Computational Chemistry
• Physical Chemistry

Background:

• Radical halogen oxides, like bromine oxide (BrO), are key players in atmospheric ozone (O3) depletion.
• Understanding the interactions of BrO with water is essential for modeling atmospheric processes, particularly in clouds.

Purpose of the Study:

• To develop an accurate computational model for the BrO-water interaction.
• To facilitate future molecular dynamics simulations of BrO in atmospheric water environments.

Main Methods:

• High-level electronic structure calculations (RCCSD(T)/aug-cc-pVQZ) were used to determine BrO-water geometries and energies.
• One-dimensional potential energy surface scans were performed for ground and excited electronic states.
• A novel analytic interaction potential was developed by modifying the Thole-type model for water.

Main Results:

• Optimized geometries and global minimum energy structure for the BrO-water complex were determined.
• A new interaction potential incorporating anisotropic atomic polarizabilities was generated.
• The potential accurately models the physics of the unpaired electron in the bromine oxide radical.

Conclusions:

• The developed BrO-water interaction potential is suitable for molecular dynamics simulations.
• This work provides a foundation for studying novel atmospheric chemistries at water interfaces.
• Accurate modeling of radical-water interactions is vital for atmospheric science.