Bismuth in gallium arsenide: Structural and electronic properties of GaAs1−xBix alloys

► Structural and electronic properties of GaAs1−xBix alloys were studied. ► We present results of lattice constant, energy gap, bulk modulus and derivative. ► The band gap decreases substantially with increasing Bi concentration. ► Calculations of the density of states and charge densities are also presented. ► We have performed calculations without and with spin-orbit coupling.