Most simulations on surfaces and interfaces consider only the most symmetri
c cases. However, it is far from clear that these interfaces are representa
tive of the general interfaces seen in practice. For surfaces, the only cer
amic systems to be studied are the stepped boundaries derived from surfaces
vicinal to the (001) boundaries of MgO and NiO. We have performed an exten
sive series of simulations to study the interfaces (both surfaces and grain
boundaries) for magnesium oxide. The objective here is both to characteris
e a variety of different kinds of steps on different surfaces and to relate
these to the binding energies of grain boundaries. We use the simulations
to discuss the general structure of grain boundaries and the adequacy of mo
dels based on highly symmetric boundaries for discussing the properties of
general boundaries.