  Weyl fermions are expected to exhibit exotic physical properties such as the
chiral anomaly, large negative magnetoresistance or Fermi arcs. Recently a new
platform to realize these fermions has been introduced based on the appearance
of a three-fold band crossing at high symmetry points of certain space groups.
These band crossings are composed of two linearly dispersed bands that are
topologically protected by a Chern number, and a at band with no topological
charge. In this paper we present a new way of inducing two kinds of Weyl
fermions, based on two- and three-fold band crossings, in the non-symmorphic
magnetic material PtFeSb. By means of density functional theory calculations
and group theory analysis we show that magnetic order can split a six-fold
degeneracy enforced by non-symmoprhic symmetry to create three-fold or two-fold
degenerate Weyl nodes. We also report on the synthesis of a related phase
potentially containing two-fold degenerate magnetic Weyl points and extend our
group theory analysis to that phase. This is the first study showing that
magnetic ordering has the potential to generate new threefold degenerate Weyl
nodes, advancing the understanding of magnetic interactions in topological
materials.
