  We perform coupled-cluster calculations for the doubly magic nuclei 4He, 16O,
40Ca and 48Ca, for neutron-rich isotopes of oxygen and fluorine, and employ
"bare" and secondary renormalized nucleon-nucleon interactions. For the
nucleon-nucleon interaction from chiral effective field theory at order
next-to-next-to-next-to leading order, we find that the coupled-cluster
approximation including triples corrections binds nuclei within 0.4 MeV per
nucleon compared to data. We employ interactions from a resolution-scale
dependent similarity renormalization group transformations and assess the
validity of power counting estimates in medium-mass nuclei. We find that the
missing contributions due to three-nucleon forces are consistent with these
estimates. For the unitary correlator model potential, we find a slow
convergence with respect to increasing the size of the model space. For the
G-matrix approach, we find a weak dependence of ground-state energies on the
starting energy combined with a rather slow convergence with respect to
increasing model spaces. We also analyze the center-of-mass problem and present
a practical and efficient solution.
