Using the procedure for the EPM, and the flow chart provided, calculate (using MATLAB) the band-structure of the following materials: Si, Ge, GaAs, Al_xGa_1-xAs (for x=0, 0.2, 0.4, 0.6, 0.8 and 1).

• Plot the bandstructure of the above materials along the high symmetry k-points in the First Brillouin zone as is done in the M. L. Cohen and T. K. Bergstresser paper.
• For the Al_xGa_1-xAs material also plot the band gap variation as a function of the mole fraction x.

Important information and steps: 1. Use the information about the high-symmetry points from the table below. Label Cartesian Coordinates Lattice Coordinates Range ( 0,0,0) O Point 4 (0, 2 x x/a , 0 ) 1/2 x (b1 + b3) 0