  The irreducible representation of band structure is important for physical
properties. Based on phonopy and recently developed SpaceGroupIrep package, we
developed a package PhononIrep, which can get the band irreducible
representation for arbitrary $\boldsymbol{k}$ point at first-principles level.
As an application, we for the first time predict the cubic crossing Dirac point
can exist in conventional crystal phonon systems X$_3$Y (X=Ti, Nb, Ta, Y=Au,
Sb). We hope this package will facilitate phonon research in the future.
