  A generalization of the Aubry-Andre model in two and three dimensions is
introduced which allows for quasiperiodic hopping terms in addition to the
quasiperiodic site potentials. This corresponds to an array of interstitial
impurities within the periodic host crystal. The resulting model is exactly
solvable and I compute the density of states and the ac-conductivity. There is
no mobility edge as in completely disordered systems but the regular
ac-conductivity and the strongly reduced Drude weight indicate a precursor of
the Anderson transition as the Fermi energy goes from the center to the band
edges.
