Cation-π interactions: accurate intermolecular potential from symmetry-adapted perturbation theory

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Molecular Interactions

Background:

• Understanding intermolecular forces is crucial for molecular modeling.
• Accurate prediction of interaction energies requires detailed analysis of contributing components.

Purpose of the Study:

• To decompose intermolecular interaction energy between ammonium cation and benzene using SAPT.
• To develop and parametrize a polarizable potential model for this system.
• To validate the model against ab initio calculations.

Main Methods:

• Symmetry-Adapted Perturbation Theory (SAPT) for energy decomposition.
• Parameterization of a polarizable potential model (AMOEBA-like).
• Inclusion of charge penetration energy term.

Main Results:

• Electrostatic and induction energies are the primary attractive forces.
• Dispersion forces contribute significantly.
• The developed polarizable model accurately reproduces ab initio interaction energies.

Conclusions:

• The proposed polarizable model provides accurate predictions for ammonium-benzene interactions.
• The energy decomposition clarifies the nature of stabilizing forces.
• This work advances the development of accurate molecular force fields.