Energetics of (H2O)20 Isomers by means of F12 Canonical and Localized Coupled Cluster Methods

Abstract

We consider the performance of combined PNO-F12 approaches for the dissociation energy of water clusters as large as (H2O)20 by comparison to canonical CCSD(T)/CBS reference values obtained through n-body decomposition of post-MP2 corrections. We find that PNO-LCCSD(T)-F12b approaches with "Tight" cutoffs are generally capable of reproducing canonical CCSD(T) interaction energies to within ~0.25% and isomerization energies to ~1.5%, while requiring only a fraction of the canonical computational cost. However, basis set convergence patterns and effect of counterpoise corrections are more erratic than for canonical calculations, highlighting the need for canonical benchmarks on closely related systems.

AIP Conference Proceedings, in press [ICCMSE-2020 issue]

References in corpus (4)

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Cited by in corpus (3)

• S66x8 Noncovalent Interactions Revisited: New Benchmark and Performance of Composite Localized Coupled-Cluster Methods
• Performance of Localized-Orbital Coupled Cluster Approaches for the Conformational Energies of Longer n-alkane Chains
• The S66 Noncovalent Interaction Benchmark Re-examined: Composite Localized Coupled Cluster Approaches