  We investigate finite particle systems of cold atoms bound in a local
potential V(r). We derive the ground state energy and the particle density
using a recently developed semiclassical theory (2008 Phys. Rev. Lett. 100
200408), and assuming the particles are described by the Haldane-Wu fractional
exclusion statistics (FES) at unitarity. This approach is applied to atoms
trapped into a three dimensional harmonic oscillator. We show that the
parameter-free FES semiclassical theory yields results that are consistent with
numerical simulations by Chang and Bertsch [2007 Phys. Rev A 76 021603(R)] and
Bulgac (2007 Phys. Rev. A 76 040502).
