  We discuss exact plaquette-ordered ground states of the generalized Hubbard
model based on the projection operator method for several corner sharing
lattices: Kagome, checkerboard, and pyrochlore lattices. The obtained exact
ground states are interpreted as N\'eel ordered states on the plaquette-located
electrons. We demonstrate that these models also have exact edge states. We
also calculate the entanglement entropy exactly in these systems.
