Transformations from ferrimagnetic to antiferromagnetic ordering with decreasing temperature have now been observed in manganese antimonides modified with V, Co, Cu, Zn, Ge, and As as well as with Cr. The magnetic structure change is accompanied by a first‐order change in the volume of the unit cell as well as a change in electrical resistivity. Crystallographic data for these materials in the exchange inversion region and at room temperature are presented as a function of the concentration of modifying element.