Double-Hybrid DFT Functionals for the Condensed Phase: Gaussian and Plane Waves Implementation and Evaluation

Area of Science:

• Computational chemistry
• Materials science
• Solid-state physics

Background:

• Intermolecular interactions are crucial in catalysis, biochemistry, and pharmacy.
• Double-hybrid density functionals (DHDFs) merge short-range density functional theory with long-range wave-function methods.
• Limited benchmark studies exist for DHDFs in condensed phases.

Purpose of the Study:

• To evaluate the performance of selected DHDFs for cohesive energies in solids.
• To assess DHDF accuracy for dispersion-dominated crystal structures.
• To investigate numerical stability and basis set effects.

Main Methods:

• Implementation of DHDFs using Gaussian and plane wave formalisms.
• Calculation of cohesive energies for four representative crystal structures.
• Analysis of basis set superposition error (BSSE) and supercell convergence.

Main Results:

• PWRB95 and ωB97X-2 functionals demonstrated excellent performance for long-range interactions in solids.
• Identified grid-dependent numerical instabilities with the PWRB95 functional.
• Discussed BSSE and convergence behavior for large basis sets.

Conclusions:

• DHDFs offer a promising approach for modeling solids with significant dispersion interactions.
• PWRB95 and ωB97X-2 are suitable candidates for such studies, with caveats regarding numerical precision.
• Further investigation into numerical stability and basis set choices is warranted.