  In a recent Letter [PRL 103, 186402 (2009)], the energy band structure of
Fe-As-based superconductors is fitted with a tight-binding model with two Fe
ions per unit cell and two degenerate xz and yz orbitals per Fe ion. The author
claims that the proposed model, which differs markedly from a model previously
used by other authors for the same two orbitals in the same compounds,
possesses the symmetry required to describe the Fe-As planes in iron-pnictide
superconductors. In this comment we argue that this is not the case.
