Improved parameterization of interatomic potentials for rare gas dimers with density-based energy decomposition...

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Interatomic Interactions

Background:

• Rare gas dimers are model systems for understanding interatomic forces.
• Accurate modeling of these interactions is crucial for various chemical and physical processes.
• Previous methods struggled to precisely delineate different contributions to interaction energies.

Purpose of the Study:

• To analyze interatomic interactions in rare gas dimers using Density-Based Energy Decomposition Analysis (DEDA).
• To develop a novel three-term molecular mechanical force field for rare gas dimers.
• To validate the force field against high-level computational data.

Main Methods:

• Utilized Density-Based Energy Decomposition Analysis (DEDA) to separate interaction components.
• Performed high-level coupled cluster calculations with single, double, and triple excitations (CCSD(T)) at the complete basis set (CBS) limit.
• Developed a new force field incorporating smeared charge multipoles, B3LYP-D3 dispersion, and Born-Mayer repulsion.

Main Results:

• DEDA confirmed that density relaxation effects are minimal in rare gas interactions.
• The developed force field accurately reproduces total interaction energies at the CCSD(T)/CBS level.
• Individual electrostatic and van der Waals components from the force field show excellent agreement with DEDA reference values.

Conclusions:

• Density-based energy decomposition analysis provides clear insights into rare gas interatomic interactions.
• The novel three-term force field offers a reliable and accurate method for modeling rare gas dimer interactions.
• This force field successfully captures both total interaction energies and individual component contributions.