Electronic structure and topological properties of centrosymmetric MoAs₂/WAs₂ from first principles

We investigate the electronic structure of group VI-B transition metal di-arsenides (TAs₂, T = Mo, W). By comparing the formation energies, the centrosymmetric di-arsenides compounds are energetically more stable, in contrast to the di-phosphorides (MoP₂/WP₂). Both compounds can be well described by a two-band model with a pair of well-separated electron/hole bands. The electron/hole carrier density is nearly compensated in MoAs2 (|n _e  - n _h |/n _h  < 1%). The [Formula: see text] classification for all partially occupied bands are topologically strong (1;001), and therefore robust surface states are expected in these materials. Using the adaptive K-mesh method, no energy degenerate state could be found except the spin degeneracy in the whole Brillouin zone, excluding the possibility of intrinsic Dirac or Weyl points near the Fermi level in the system.