  Symmetry analysis of the Dzyaloshinskii-Moriya (DM) interaction in MnSi-type
cubic crystals demonstrates that the magnetic moments are tilted periodically,
producing a weak antiferromagnetic pattern, when the helix is unwound by
magnetic field. The tilt angles of four Mn sublattices are determined by a
component of the DM vector perpendicular to that one responsible for helical
spiraling; both components have been evaluated using a simple model. It is
shown that the tilting should induce pure magnetic reflections 00l, l=2n+1 in
neutron or x-ray magnetic scattering, and the structure factors of these
"forbidden" reflections are calculated for arbitrary field orientations.
