Comment on "Doping Driven (π,0) Nesting and Magnetic Properties of Fe_(1+x)Te Superconductors" [Phys. Rev. Lett. 103, 067001 (2009)]

In this Comment, using Korringa-Kohn-Rostoker coherent-potential approximation method in the atomic-sphere approximation (KKR-ASA CPA) to describe the effects of disorder due to excess Fe in FeTe alloys, we show that (i) the rigid-band approximation is inadequate to describe the effects of disorder and its application leads to an incorrect description of the underlying physics, (ii) the rigid-band energy shift of ~0.76 eV for going from FeTe to Fe_{1.068}Te (or Fe_{1.063}Te), as obtained by Han and Savrasov (Phys. Rev. Lett. 103, 067001(2009)), is inconsistent with our FP-LMTO as well as the KKR-ASA results, and thus the FS of Fe_{1.063}Te shown in Fig. 3(b) of their paper is not correct.