  The layered structure of the iron based superconductors gives rise to a more
or less pronounced two-dimensionality of their electronic structure, most
pronounced in LaOFeAs. A consequence are distinct surface states to be expected
to influence any surface sensitive experimental probe. In this work a detailed
density functional analysis of the cleavage behavior and the surface electronic
structure of LaOFeAs is presented. The surface states are obtained to form
two-dimensional bands with their own Fermi surfaces markedly different from the
bulk electronic structure.
