  We construct a model of phantom energy using the graded Lie algebra SU(2/1).
The negative kinetic energy of the phantom field emerges naturally from the
graded Lie algebra, resulting in an equation of state with w<-1. The model also
contains ordinary scalar fields and anti-commuting (Grassmann) vector fields
which can be taken as two component dark matter. A potential term is generated
for both the phantom fields and the ordinary scalar fields via a postulated
condensate of the Grassmann vector fields. Since the phantom energy and dark
matter arise from the same Lagrangian the phantom energy and dark matter of
this model are coupled via the Grassman vector fields. In the model presented
here phantom energy and dark matter come from a gauge principle rather than
being introduced in an ad hoc manner.
