SEARCH Articles Figures Tables Brillouin-Wigner coupled cluster single-root multi-reference Brillouin-Wigner coupled cluster theory single-reference Brillouin-Wigner perturbation theory single-reference Configuration interaction theory single-reference Brillouin-Wigner Multi-reference Brillouin-Wigner coupled cluster single- and Multi-reference Brillouin-Wigner coupled-cluster theory, single-root Multi-reference Brillouin-Wigner single-root Single reference Brillouin-Wigner expansions Single-reference Single-root formulation of multi-reference Brillouin-Wigner perturbation theory Single-root formulation of the multi-reference Brillouin-Wigner coupled-cluster theory Single-root multi-reference Brillouin-Wigner coupled cluster theory Hilbert space approach