Modeling systems with π-π interactions using the Hartree-Fock method with an empirical dispersion correction

Area of Science:

• Computational chemistry
• Quantum chemistry
• Molecular modeling

Background:

• Accurate modeling of molecular interactions is crucial in computational chemistry.
• Higher-level electronic structure theories provide high accuracy but are computationally expensive.
• Developing cost-efficient methods for studying systems with π-π interactions is an ongoing challenge.

Purpose of the Study:

• To evaluate the accuracy of the Hartree-Fock method with empirical dispersion correction (HF-D3) for modeling interaction energies and geometries.
• To compare HF-D3 performance against conventional correlation methods (e.g., MP2) and the effective fragment potential model.
• To assess the suitability of HF-D3 for systems exhibiting π-π interactions.

Main Methods:

• Application of HF-D3 to substituted-benzene dimers in various configurations (sandwich, T-shaped).
• Application of HF-D3 to DNA base pair complexes in different geometries (hydrogen-bonded, stacked).
• Comparison of HF-D3 results with established methods like second-order perturbation theory and coupled cluster theory.

Main Results:

• HF-D3 demonstrates good accuracy in modeling interaction energies and minimum energy geometries.
• The method performs comparably to more computationally intensive methods for the studied systems.
• HF-D3 is found to be particularly effective for systems with significant π-π interactions.

Conclusions:

• HF-D3 serves as a plausible and cost-efficient alternative to higher levels of electronic structure theory for systems with π-π interactions.
• The method offers a balance between accuracy and computational cost.
• HF-D3 is a valuable tool for molecular modeling studies involving aromatic systems and DNA base pairs.