Local embedding of coupled cluster theory into the random phase approximation using plane waves.

Area of Science:

• Computational Chemistry
• Materials Science
• Quantum Mechanics

Background:

• Accurate treatment of electron correlation is vital for predicting material properties.
• Periodic boundary conditions are essential for modeling bulk materials and surfaces.
• Embedding methods offer a way to combine high accuracy for local regions with efficiency for the environment.

Purpose of the Study:

• To present a novel embedding approach for local electron correlation in periodic systems.
• To enable accurate and efficient calculations of adsorption and formation energies.
• To validate the method for various chemical and physical scenarios.

Main Methods:

• A plane wave-based embedding scheme combining high-level Coupled Cluster (CC) theory with localized orbitals.
• Integration into a low-level direct Random Phase Approximation (RPA) correlation calculation.
• Application to adsorption energies of molecules on surfaces and in crystal cages, and impurity formation energies.

Main Results:

• The embedding scheme accurately treats local electron correlation and long-range dispersion effects.
• Accelerated convergence observed when high-level and low-level dispersion models are similar (CC and RPA).
• Achieved sub-20 meV accuracy for methane adsorption in chabazite at the CC level.
• Successfully applied to a large system of water adsorption on titania.

Conclusions:

• The presented embedding approach provides a consistent and efficient framework for electronic structure calculations in periodic systems.
• It enables highly accurate predictions of adsorption and formation energies.
• The method is scalable and applicable to complex, large-scale systems relevant to materials science.