Comment on “Magnetic structure of Gd2Ti2O7”

M. W. Long and collaborators [ Phys. Rev. B 83 054422 (2011)] recently proposed magnetic structures for gadolinium titanate that differ from those previously reported by us [ J. R. Stewart, G. Ehlers, A. S. Wills, S. T. Bramwell and J. S. Gardner J. Phys.: Condens. Matter 16 L321 (2004)]. In this Comment, we show that the calculated structure factors, S(Q), of the newly proposed models are inconsistent with our neutron powder diffraction data. Long and colleagues were led to reconsider the magnetic structure of gadolinium titanate on the basis of a number of theoretical and experimental assumptions. We argue that these assumptions have no basis in fact and conclude that they provide no reason to doubt our published magnetic structures.