Ground state analytical ab initio intermolecular potential for the Cl(2)-water system.

Area of Science:

• Atmospheric Chemistry
• Physical Chemistry
• Computational Chemistry

Background:

• The chlorine/water interface is vital for atmospheric chemistry.
• Accurate potential energy surfaces are needed to model interface structure and dynamics.

Purpose of the Study:

• To develop an analytical intermolecular potential for Cl2-water interactions.
• To model the physisorption of Cl2 on hexagonal ice.

Main Methods:

• High-level ab initio calculations using coupled-cluster single double (triple)/aug-cc-p-VTZ.
• Fitting an analytical functional form to reproduce Cl2-H2O complex structures.
• Validation against ab initio data for increasing numbers of water molecules.

Main Results:

• An analytical intermolecular potential for Cl2-water interactions was developed.
• The potential accurately reproduces three minima structures of the 1:1 complex.
• Calculated adsorption energy for Cl2 on ice is 0.27 eV, matching experimental data.

Conclusions:

• The developed model potential accurately describes Cl2-water interactions.
• The model is suitable for studying Cl2 physisorption on ice surfaces.
• This work advances the understanding of atmospheric chemistry at interfaces.