Harmonically trapped jellium
  We discuss the model of a $D$-dimensional confined electron gas in which the particles are trapped by a harmonic potential. In particular, we study the non-interacting kinetic and exchange energies of finite-size inhomogeneous systems, and compare the resulting Thomas-Fermi and Dirac coefficients with various uniform electron gas paradigms. We show that, in the thermodynamic limit, the properties of this model are identical to those of the $D$-dimensional Fermi gas. 
Pierre-Fran\c{c}ois Loos and Peter M. W. Gill
physics.chem-ph cond-mat.other cond-mat.quant-gas cond-mat.str-el