On the distinguishable cluster approximation for triple excitations

Abstract

The distinguishable cluster approximation applied to coupled cluster doubles equations greatly improves absolute and relative energies. We apply the same approximation to the triples equations and demonstrate that it can also improve results of the coupled cluster with singles, doubles and triples. The resulting method has a nominal computational scaling of $\mathcal{O}(N^7)$ in the real-space representation, is orbital invariant, size extensive, and exact for three electrons.

References in corpus (4)

• The distinguishable cluster approximation
• Low rank factorization of the Coulomb integrals for periodic coupled cluster theory
• Ab initio potential energy curve for the ground state of beryllium dimer
• Lowering of the complexity of quantum chemistry methods by choice of representation

Cited by in corpus (9)

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• Transcorrelated coupled cluster methods. II. Molecular systems
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• Unveiling Intrinsic Many-Body Complexity by Compressing Single-Body Triviality
• Orbital optimisation in xTC transcorrelated methods
• "Best" iterative coupled-cluster triples model: More evidence for 3CC
• Two Determinant Distinguishable Cluster
• Addressing Strong Correlation by Approximate Coupled-Pair Methods with Active-Space and Full Treatments of Three-Body Clusters