  A central difficulty of state-specific Multi-Reference Coupled Cluster
(MR-CC) formalisms concerns the definition of the amplitudes of the single and
double excitation operators appearing in the exponential wave operator. If the
reference space is a complete active space (CAS) the number of these amplitudes
is larger than the number of singly and doubly excited determinants on which
one may project the eigenequation, and one must impose additional conditions.
The present work first defines a state-specific reference-independent operator
$\hat{\tilde{T}}^m$ which acting on the CAS component of the wave function
$|\Psi_0^m \rangle$ maximizes the overlap between
$(1+\hat{\tilde{T}}^m)|\Psi_0^m \rangle$ and the eigenvector of the CAS-SD CI
matrix $|\Psi_{\rm CAS-SD}^m \rangle$. This operator may be used to generate
approximate coefficients of the Triples and Quadruples, and a dressing of the
CAS-SD CI matrix, according to the intermediate Hamiltonian formalism. The
process may be iterated to convergence. As a refinement towards a strict
Coupled Cluster formalism, one may exploit reference-independent amplitudes
provided by $(1+\hat{\tilde{T}}^m)|\Psi_0^m \rangle$ to define a
reference-dependent operator $\hat{T}^m$ by fitting the eigenvector of the
(dressed) CAS-SD CI matrix. The two variants, which are internally
uncontracted, give rather similar results. The new MR-CC version has been
tested on the ground state potential energy curves of 6 molecules (up to
triple-bond breaking) and a two excited states. The non-parallelism error with
respect to the Full-CI curves is of the order of 1 m$E_{\rm h}$.
