  The spontaneous Hall effect is usually governed by three conventional
mechanisms, such as the Berry curvature, skew scattering and side jump, which
widely exist in ferromagnetic or antiferromagnetic materials. However, in this
work, based on first principle calculations, we predict a giant crystal Hall
effect (CHE) in the antiferromagnetic $\gamma$-FeMn, which can not be
understood by the previous three conventional mechanisms and the Hall angle
therein can be as large as 18.4% at low temperature. Furthermore, with
Boltzmann transport equation and a tight-binding model, we conclude that, the
asymmetric group velocities on Fermi surface is the origin of this CHE in
$\gamma$-FeMn. And with a systematic symmetry argument, we show that, this
unusual effect is not dependent on specific materials but universal in any
crystals with similar symmetry even without local magnetization.
