Comment on 'Electronic structure and zone-center phonon modes in multiferroic bulk BiFeO3' [J. Appl. Phys. 103, 083712 (2008)]

In a recent paper, Tutuncu and Srivastava [J. Appl. Phys. 103, 083712 (2008)] report the electronic structure and the assignment of the zone-center phonon modes of the R3c phase of BiFeO3 using the density functional theory. In the present comment, we point out some physical inaccuracies in their mode assignment. We review their interpretation and analyze which conclusions are actually justified.