Topological Weyl semimetal phases in a time reversal invariant spinless model

We investigate the topological Weyl semimetal phases in a time reversal invariant spinless lattice model which hasC_4vorC_2vpoint group symmetries. For theC_4vcase, the model is characterized by eight Weyl points in thek_z=πplane, while for theC_2vcase, it is characterized by four Weyl points in thek_z=πplane. For both cases, Fermi arcs can be realized on their surfaces. We find that the topological Weyl semimetal can be viewed as an intermediate phase between the topological crystalline insulator (TCI) and normal insulator, and they all can be described by the so-called bent mirror Chern numbers. What's more, in theC_2vcase, the TCI phase is still present when the perturbation is small, though theZ₂invariant is not well-defined then, however, it can be well described by the bent mirror Chern number.