  Bilayer graphene has been a subject of intense study in recent years. We
extend a structural phase field crystal method to include an external potential
from adjacent layer(s), which is generated by the corresponding phase field and
changes over time. Moreover, multiple layers can be added into the structure.
Using the thickness of the boundaries between different stacking variants of
the bilayer structure as the key parameter, we quantify the strength of the
adjacent layer potential by comparing with atomistic simulation results. We
then test the multiple graphene structures, including bilayers, triple layers,
up to 6 layers. We find that besides the initial conditions, the way of new
layers added into the structure will also affect the layout of the atomic
configuration. We believe tour results can help understanding the mechanism of
graphene structure consists of more than one layer.
