  We analyze triply degenerate nodal points [or triple points (TPs) for short]
in energy bands of crystalline solids. Specifically, we focus on spinless band
structures, i.e., when spin-orbit coupling is negligible, and consider TPs
formed along high-symmetry lines in the momentum space by a crossing of three
bands transforming according to a 1D and a 2D irreducible corepresentation
(ICR) of the little co-group. The result is a complete classification of such
TPs in all magnetic space groups, including the non-symmorphic ones, according
to several characteristics of the nodal-line structure at and near the TP. We
show that the classification of the presently studied TPs is exhausted by 13
magnetic point groups (MPGs) that can arise as the little co-group of a
high-symmetry line and which support both 1D and 2D spinless ICRs. For 10 of
the identified MPGs, the TP characteristics are uniquely determined without
further information; in contrast, for the 3 MPGs containing sixfold rotational
symmetry, two types of TPs are possible, depending on the choice of the
crossing ICRs. The classification result for each of the 13 MPGs is illustrated
with first-principles calculations of a concrete material candidate.
