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dc.contributor.authorShepherd, James J.
Henderson, Thomas M.
Scuseria, Gustavo E.
dc.date.accessioned 2017-05-24T16:33:35Z
dc.date.available 2017-05-24T16:33:35Z
dc.date.issued 2014
dc.identifier.citation Shepherd, James J., Henderson, Thomas M. and Scuseria, Gustavo E.. "Coupled cluster channels in the homogeneous electron gas." The Journal of Chemical Physics, 140, no. 12 (2014) http://dx.doi.org/10.1063/1.4867783.
dc.identifier.urihttp://hdl.handle.net/1911/94376
dc.description.abstract We discuss diagrammatic modifications to the coupled cluster doubles (CCD) equations, wherein different groups of terms out of rings, ladders, crossed-rings, and mosaics can be removed to form approximations to the coupled cluster method, of interest due to their similarity with various types of random phase approximations. The finite uniform electron gas (UEG) is benchmarked for 14- and 54-electron systems at the complete basis set limit over a wide density range and performance of different flavours of CCD is determined. These results confirm that rings generally overcorrelate and ladders generally undercorrelate; mosaics-only CCD yields a result surprisingly close to CCD. We use a recently developed numerical analysis [J. J. Shepherd and A. Grüneis, Phys. Rev. Lett. 110, 226401 (2013)] to study the behaviours of these methods in the thermodynamic limit. We determine that the mosaics, on forming the Brueckner one-body Hamiltonian, open a gap in the effective one-particle eigenvalues at the Fermi energy. Numerical evidence is presented which shows that methods based on this renormalisation have convergent energies in the thermodynamic limit including mosaic-only CCD, which is just a renormalised MP2. All other methods including only a single channel, namely, ladder-only CCD, ring-only CCD, and crossed-ring-only CCD, appear to yield divergent energies; incorporation of mosaic terms prevents this from happening.
dc.language.iso eng
dc.rights Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
dc.title Coupled cluster channels in the homogeneous electron gas
dc.type Journal article
dc.citation.journalTitle The Journal of Chemical Physics
dc.citation.volumeNumber 140
dc.citation.issueNumber 12
dc.contributor.publisher AIP Publishing
dc.type.dcmi Text
dc.identifier.doihttp://dx.doi.org/10.1063/1.4867783
dc.identifier.pmid 24697419
dc.type.publication publisher version
dc.citation.articleNumber 124102


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