  Ab initio nuclear physics tackles the problem of strongly interacting
four-component fermions. The same setting could foreseeably be probed
experimentally in ultracold atomic systems, where two- and three-component
experiments have led to major breakthroughs in recent years. Both due to the
problem's inherent interest and as a pathway to nuclear physics, in this Letter
we study four-component fermions at unitarity via the use of quantum Monte
Carlo methods. We explore novel forms of the trial wave function and find one
which leads to a ground state of the eight-particle system whose energy is
almost equal to that of two four-particle systems. We investigate the
clustering properties involved and also extrapolate to the zero-range limit. In
addition to being experimentally testable, our results impact the prospects of
developing nuclear physics as a perturbation around the unitary limit.
