Ground-States for Metals from Converged Coupled Cluster Calculations

TL;DR

This paper introduces a new coupled cluster approach to accurately compute the ground-state energies of bulk metals, demonstrating convergence and agreement with experimental data, thus enabling more efficient modeling of metallic materials.

Contribution

A novel scheme to reach the thermodynamic limit of metallic ground-state energies using coupled cluster theory with weak long-range and short-range correlation coupling.

Findings

Successfully calculated surface energies of aluminum and platinum (111).

Achieved convergence with respect to finite-size effects, basis-set size, and coupled cluster expansion.

Results show excellent agreement with experimental data.

Abstract

Many-electron correlation methods offer a systematic approach to predicting material properties with high precision. However, practically attaining accurate ground-state properties for bulk metals presents significant challenges. In this work, we propose a novel scheme to reach the thermodynamic limit of the total ground-state energy of metals using coupled cluster theory. We demonstrate that the coupling between long-range and short-range contributions to the correlation energy is sufficiently weak, enabling us to restrict long-range contributions to low-energy excitations in a controllable way. Leveraging this insight, we calculate the surface energy of aluminum and platinum (111), providing numerical evidence that coupled cluster theory is well-suited for modeling metallic materials, particularly in surface science. Notably, our results exhibit convergence with respect to finite-size effects, basis-set size, and coupled cluster expansion, yielding excellent agreement with experimental data. This paves the way for more efficient coupled cluster calculations for large systems and a broader utilization of the theory in realistic metallic models of materials.