Communication: Charge-population based dispersion interactions for molecules and materials

Area of Science:

• Computational Chemistry
• Materials Science

Background:

• Accurate calculation of C6 coefficients and polarizabilities is crucial for modeling intermolecular interactions.
• Existing methods often rely on electron-density partitioning, limiting their applicability.
• Dispersion corrections are essential for describing van der Waals forces in electronic structure calculations.

Purpose of the Study:

• To develop a system-independent method for deriving effective atomic C6 coefficients and polarizabilities.
• To enable the use of dispersion-correction schemes with semi-empirical methods and tight-binding Hamiltonians.
• To assess the accuracy of the proposed method against established approaches.

Main Methods:

• Derivation of C6 coefficients and polarizabilities from charge population analysis.
• Integration of a many-body dispersion method with the semi-empirical density functional tight-binding (DFTB) method.
• Application to weakly bound molecular dimers, organic crystals, and supramolecular complexes.

Main Results:

• The proposed method accurately describes intermolecular C6 coefficients and dispersion energies.
• Achieved accuracy is comparable to electron-density partitioning-based methods.
• Demonstrated successful incorporation of many-body dispersion into DFTB.

Conclusions:

• The charge population analysis-based method provides a robust and versatile approach for dispersion corrections.
• The developed DFTB-based many-body dispersion method is suitable for studying complex systems like hybrid organic-inorganic interfaces.
• This work expands the applicability of dispersion-corrected electronic structure calculations to a wider range of methods and systems.