Simplified DFT methods for consistent structures and energies of large systems.

Area of Science:

• Computational chemistry
• Materials science
• Solid-state physics

Background:

• Kohn-Sham density functional theory (DFT) is crucial for electronic structure calculations of large systems.
• Accurate geometries and non-covalent interactions are essential for understanding molecular crystals.
• Existing DFT methods can be computationally expensive for very large systems.

Purpose of the Study:

• To present a hierarchy of simplified DFT methods tailored for large molecular crystals.
• To enable consistent structure and non-covalent interaction calculations.
• To provide computationally efficient yet accurate tools for materials science.

Main Methods:

• Development of simplified DFT methods: Hartree-Fock (HF-3c), screened exchange hybrid (HSE-3c), and generalized gradient approximation (B97-3c).
• Augmentation of methods with semi-classical correction potentials.
• Evaluation using established benchmark sets for molecular crystal geometries and lattice energies.

Main Results:

• The simplified DFT methods demonstrate good performance for geometries and lattice energies of molecular crystals.
• HF-3c, HSE-3c, and B97-3c provide accurate results for large organic crystals.
• Successful application to systems containing hundreds of atoms in the primitive unit cell.

Conclusions:

• The presented hierarchy of simplified DFT methods offers a computationally efficient approach for large molecular crystals.
• These methods are suitable for reliable geometry optimization and prediction of non-covalent interactions.
• They represent a valuable tool for computational studies in materials science and condensed matter physics.