Monolayers of group VA elements have attracted great attention with the
rising of black phosphorus. Here, we derive a simple tight-binding model for
monolayer grey arsenic, referred as arsenene (ML-As), based on the
first-principles calculations within the partially self-consistent GW0
approach. The resulting band structure derived from the six p-like orbitals
coincides with the quasi-particle energy from GW0 calculations with a high
accuracy. In the presence of a perpendicular magnetic field, ML-As exhibits two
sets of Landau levels linear with respect to the magnetic field and level
index. Our numerical calculation of the optical conductivity reveals that the
obtained optical gap is very close to the GW0 value and can be effectively
tuned by external magnetic field. Thus, our proposed TB model can be used for
further large-scale simulations of the electronic, optical and transport
properties of ML-As