We report first-principles calculations at $\overline{\Gamma }$ for a (001) iron thin film. Four different potentials have been investigated, and we find for the first time that the existence and symmetry of surface states depends crucially on details of the potential. For the potential which we consider most physical we find a surface state which peaks more than one-half layer outside the last plane of atoms.

• Received 4 June 1975

DOI:https://doi.org/10.1103/PhysRevLett.35.738