  Intuitively, the dispersion characteristics of Weyl nodes with opposite
charges in single-pair charge-2 Weyl semimetals are the same, quadratic or
linear. We theoretically predicted that single-pair hybrid charge-2 Weyl
semimetals (the nodes with opposite charges show quadratic Weyl and linear
charge-2 Dirac characteristics, respectively) can be protected by specific
nonsymmorphic symmetries in spinless systems. Moreover, the symmetries force
the pair of Weyl points locate at the center and corners of the first Brillouin
zone (FBZ), respectively. Consequently, nontrivial surface states run through
the entire FBZ of the system fascinating for future experimental detection and
device applications. The hybrid phase is further verified with the help of
first-principles calculations for the phonon states in realistic material of
Na$_2$Zn$_2$O$_3$. The new phase will not only broaden the understanding of the
Weyl semimetals, but also provide an interesting platform to investigate the
interaction between the two types of Weyl fermions with different dispersions.
