Applying the Coupled-Cluster Ansatz to Solids and Surfaces in the Thermodynamic Limit

Thomas Gruber,Felix Hummel,Theodoros Tsatsoulis,Ke Liao,Andreas Grüneis

doi:10.1103/physrevx.8.021043

Thomas Gruber, Felix Hummel + Show 3 more

Open Access

https://doi.org/10.1103/physrevx.8.021043

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Abstract

Modern electronic structure theories can predict and simulate a wealth of phenomena in surface science and solid-state physics. In order to allow for a direct comparison with experiment, such ab initio predictions have to be made in the thermodynamic limit, substantially increasing the computational cost of many-electron wave-function theories. Here, we present a method that achieves thermodynamic limit results for solids and surfaces using the "gold standard" coupled cluster ansatz of quantum chemistry with unprecedented efficiency. We study the energy difference between carbon diamond and graphite crystals, adsorption energies of water on h-BN, as well as the cohesive energy of the Ne solid, demonstrating the increased efficiency and accuracy of coupled cluster theory for solids and surfaces.

Highlights

Modern ab initio methods to solve the electronic Schrödinger equation for real solids and molecules such as density functional theory or wave-function-based methods are becoming increasingly accurate and efficient [1,2,3,4]
We find that calculations using 16 orbitals per carbon atom yield an energy difference that agrees to within 4 meV=atom compared to results obtained using 40 natural orbitals per atom
We have introduced an efficient and accurate thermodynamic limit correction for wavefunction-based theory calculations of solids and surfaces that is free of adjustable parameters and easy to implement

Summary

INTRODUCTION

Modern ab initio methods to solve the electronic Schrödinger equation for real solids and molecules such as density functional theory or wave-function-based methods are becoming increasingly accurate and efficient [1,2,3,4]. The convergence towards the thermodynamic limit with respect to the number of particles is very slow, often exceeding the computational resources of even modern supercomputers This is the case for many-electron wave-function-based theories that allow for a systematic improvability upon the description of the electronic correlation energy. Theories that approximate long-range correlation effects such as van der Waals interactions must carefully be checked for convergence with respect to the employed cutoff parameters to allow for accurate and predictive ab initio studies of real materials This is of particular importance in condensed-matter systems where the accumulation of weak van der Waals interactions can become a non-negligible contribution to the property of interest, as, for example, in the case of the energy difference between carbon diamond and graphite or the adsorption of a water molecule on an h-BN sheet. Because of the adverse scaling of the computational complexity in coupled cluster theories, the proposed method allows for reducing the computational cost by several orders of magnitude without compromising accuracy compared to previous studies [4]

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RESULTS

CONCLUSION AND OUTLOOK