  Recently, multifold fermions characterized by band crossings with multifold
degeneracy and Fermi surfaces with nontrivial Chern numbers have been
discovered experimentally in AlPt[arXiv:1812.03310] and
XSi(X=Rh,Co)[arXiv:1812.04466][arXiv:1901.03358][arXiv:1809.01312]. In this
work, we largely expand the family of multifold fermion materials by pointing
out that several well-studied noncentrosymmetric superconductors are indeed
multifold fermion metals. Importantly, their normal state topological
properties, which have been ignored in previous studies, play an important role
in the superconducting properties. Taking Li$_2$Pd$_3$B and Li$_2$Pt$_3$B as
examples, we found a large number of unconventional degenerate points, such as
double spin-1, spin-3/2, Weyl and double Weyl topological band crossing points
near the Fermi energy, which result in finite Chern numbers on Fermi surfaces.
Long Fermi arc states in Li$_2$Pd$_3$B, originating from the nontrivial band
topology were found. Importantly, it has been shown experimentally that
Li$_2$Pd$_3$B and Li$_2$Pt$_3$B are fully gapped and gapless superconductors,
respectively. By analyzing the possible pairing symmetries, we suggest that
Li$_2$Pd$_3$B can be a DIII class topological superconductor with Majorana
surface states, even though the spin-orbit coupling in Li$_2$Pd$_3$B is
negligible. Interestingly, Li$_2$Pt$_3$B, being gapless, is likely to be a
nodal topological superconductor with dispersionless surface Majorana modes. We
further identified that several noncentrosymmetric superconductors, such as
Mo$_3$Al$_2$C, PdBiSe, Y$_2$C$_3$ and La$_2$C$_3$, are multifold fermion
superconductors whose normal state topological properties have been ignored in
previous experimental and theoretical studies.
