  We use the recently proposed In-Medium Similarity Renormalization Group
(IM-SRG) to carry out a systematic study of closed-shell nuclei up to
$\nuc{Ni}{56}$, based on chiral two- plus three-nucleon interactions. We
analyze the capabilities of the IM-SRG by comparing our results for the
ground-state energy to Coupled Cluster calculations, as well as to quasi-exact
results from the Importance-Truncated No-Core Shell Model. Using chiral two-
plus three-nucleon Hamiltonians whose resolution scales are lowered by
free-space SRG evolution, we obtain good agreement with experimental binding
energies in $\nuc{He}{4}$ and the closed-shell oxygen isotopes, while the
calcium and nickel isotopes are somewhat overbound.
