  We discuss computational aspects of the spherical coupled-cluster method
specific to the nuclear many-body problem. Using chiral nucleon-nucleon
interaction at next-to-next-to-next-to leading order (N3LO) with cutoff Lambda
= 500MeV, we present coupled-cluster results for the ground state of 40Ca.
Scaling and performance studies are presented together with challenges we meet
with when extending the coupled-cluster effort to nuclei mass hundred and
beyond.
