 This model showed why the density of conduction electrons (as represented by the Wigner–Seitz radius "rs") is an important parameter in determining work function.The jellium model is only a partial explanation, as its predictions still show significant deviation from real work functions.More recent models have focused on including more accurate forms of electron exchange and correlation effects, as well as including the crystal face dependence (this requires the inclusion of the actual atomic lattice, something that is neglected in the jellium model).