  The occurrence of superconducting and insulating phases is well-established
in twisted graphene bilayers, and they have also been reported in other
arrangements of graphene layers. We investigate three such arrangements:
untwisted AB bilayer graphene on an hBN substrate, two graphene bilayers
twisted with respect to each other, and a single ABC stacked graphene trilayer
on an hBN substrate. Narrow bands with different topology occur in all cases,
producing a high density of states which enhances the role of interactions. We
investigate the effect of the long range Coulomb interaction, treated within
the self consistent Hartree-Fock approximation. We find that the on-site part
of the Fock potential strongly modifies the band structure at charge
neutrality. The Hartree part does not significantly modify the shape and width
of the bands in the three cases considered here, in contrast to the effect that
such a potential has in twisted bilayer graphene.
