SEARCH Articles Figures Tables Brillouin-Wigner coupled cluster theory single-reference Cluster coupled Coupled clustered theory Coupled-cluster theory Coupling theory Multi-reference Brillouin-Wigner coupled-cluster theory, single-root Single reference restricted coupled cluster theory Single reference unrestricted coupled cluster theory Single-reference Single-root formulation of the multi-reference Brillouin-Wigner coupled-cluster theory Single-root multi-reference Brillouin-Wigner coupled cluster theory Hilbert space approach