These arguments explain why k = 0 ordering is not adopted in Ni 4 V 3 O 10 . The magnetic peak assigned to Ni 4 V 3 O 10 at d = 5.57 Å could be indexed as (003) under the assumption of c-axis doubling, resulting in a magnetic propagation vector k = (0, 0, 2 ), but this assumption also produces structures incompatible with antiferromagnetic ordering and does not index the remaining neutron diffraction peaks.