Coupled-Cluster Density-Based Many-Body Expansion.

ABSTRACT: While CCSD(T) is often considered the "gold standard" of computational chemistry, the scaling of its computational cost as N⁷ limits its applicability for large and complex molecular systems. In this work, we apply the density-based many-body expansion [ Int. J. Quantum Chem. 2020, 120, e26228] in combination with CCSD(T). The accuracy of this approach is assessed for neutral, protonated, and deprotonated water hexamers, as well as (H₂O)₁₆ and (H₂O)₁₇ clusters. For the neutral water clusters, we find that already with a density-based two-body expansion, we are able to approximate the supermolecular CCSD(T) energies within chemical accuracy (4 kJ/mol). This surpasses the accuracy that is achieved with a conventional, energy-based

SUBMITTER: Focke K 

PROVIDER: S-EPMC10626589 | biostudies-literature | 2023 Nov

REPOSITORIES: biostudies-literature