Dear Martin,
because of the non-variational nature of Coupled-Cluster response theory (or equivalently EOM-CC theory) , the excited states
are described by eigenvalues and eigenvectors of the non-hermitian matrix. Therefore left and right eigenvectors are
different and on get different left and right transition moments and left and right transition densities, which don't have
on there one a physical meaning. Only the product of left and right transition moments in related to observable.
In short: the results for CC2 (or any other CC) calculation on transition moments can not be cast into such simple
representation with a single transition density (or you have to make some approximations). This is only possible for variational methods.
Christof