  Higher-fold chiral fermions that go beyond two-fold Weyl fermions have
recently been reported in crystalline systems. Here, we focus on such
excitations in several binary, ternary and quaternary alloys/compounds with
CoGe, BiSbPt and KMgBO3 as the representative examples that belong to the
crystal space group (SG) 198. We found distinct three-fold, four-fold and
six-fold chiral fermions in the bulk via Density Functional computations. We
provide general symmetry arguments for the protection of these degeneracies
with special emphasis on the four-fold fermions. Our surface spectra
simulations show that the size of Fermi arcs resulting from these chiral
fermions are large, robust and untouched from the bulk states due to the near
absence of trivial bulk Fermi pockets. All these features make these systems --
especially CoGe and KMgBO3 -- promising topological semimetal candidates to
realize higher-fold fermions in future photo-emission and transport
experiments.
