In oder to understand our universe, we built large research facilities such as the LHC in Switzerland, which can be used to find new particles. In the solid state, such particles can exist as quasiparticles, which makes them more easily accessible. The presence of unusual quasiparticles in a material depends on its electronic structure. We predicted with group theory that materials that crystallize in the pyrite crystal structure should host yet undiscovered types of fermions. But this prediction strongly relies on the magnetic space group. Since neutron diffraction studies on transition metal pyrites have only been performed on low resolution instruments, we would like to reinvestigate the magnetic structure of two promising candidates, NiS2 and MnTe2. This study will help us to back up our prediction and move forward towards experimental verification of these new quasiparticles.