SEARCH Articles Figures Tables Brillouin-Wigner coupled cluster single-root multi-reference Brillouin-Wigner coupled cluster singles Brillouin-Wigner coupled cluster theory multi-reference Brillouin-Wigner coupled cluster theory single-reference Brillouin-Wigner coupled-cluster theory Brillouin-Wigner coupled-cluster theory Hilbert space approach Brillouin-Wigner coupled-clusters Brillouin-Wigner theory Cluster approach Cluster coupled Cluster roots Clustering space Coupled cluster approach Coupled clustered theory Coupled-cluster theory Coupling theory Couplings spacing Hilbert space Multi couplings Multi-reference approaches Multi-reference coupled-cluster Reference spaces Single reference Brillouin-Wigner Single-reference Single-reference coupled-cluster theory Space theory