Mixed Gaussian and plane wave basis set implementation of the random phase approximation and of σ-functionals within...

Area of Science:

• Computational Chemistry
• Materials Science
• Quantum Chemistry

Background:

• The accuracy of computational methods is crucial for predicting molecular and material properties.
• The mixed Gaussian and plane wave (GPW) basis set scheme offers a computationally efficient approach.
• Evaluating advanced methods like Random Phase Approximation (RPA) and σ-functional methods within GPW is essential.

Purpose of the Study:

• To assess the reliability of RPA and σ-functional methods with the GPW scheme in the CP2K package.
• To establish dependable computational setups for practical applications in chemistry and materials science.
• To compare these advanced methods against standard approaches for molecular and crystalline solid properties.

Main Methods:

• Investigated thermochemical properties of molecules and structural properties of crystalline solids.
• Employed the mixed Gaussian and plane wave (GPW) basis set scheme within the CP2K package.
• Compared results from RPA and σ-functional calculations against standard Gaussian basis sets and the Perdew-Burke-Ernzerhof (PBE) method.

Main Results:

• For molecules, GPW-based RPA and σ-functional methods showed comparable, though slightly lower, accuracy than standard Gaussian basis sets.
• GPW σ-functional calculations outperformed RPA and conventional Kohn-Sham methods for reaction energies and barrier heights in main group chemistry.
• RPA and σ-functional methods significantly improved lattice constant predictions for crystalline solids compared to PBE; RPA also improved bulk moduli.

Conclusions:

• RPA and σ-functional methods, when used with the GPW scheme, offer reliable and often superior alternatives for computational studies.
• These methods demonstrate particular strengths in predicting reaction energetics and solid-state structural parameters.
• The GPW scheme provides a viable and efficient framework for employing advanced quantum chemical methods.