Consider a three-dimensional crystalline lattice formed of Cu and Zn atoms. The Cu atoms form a simple cubic lattice with the lattice constant a. The Zn atoms are at the center of the cube. a) Write down the structure factor S, associated with the reciprocal lattice vector G = vib1 + vzb2 + v3b3 in terms of the atomic form factors f and f, b) If Cu and Zn atoms randomly occupy every lattice site, then the form factor associated with every lattice site can be assumed to be the same, namely the average of the two form factors. Which Bragg spots will vanish in this case?

Consider a three-dimensional crystalline lattice formed of Cu and Zn atoms. The Cu atoms form a simple cubic lattice with the lattice constant a. The Zn atoms are at the center of the cube. a) Write down the structure factor S, associated with the reciprocal lattice vector G = vib1 + vzb2 + v3b3 in terms of the atomic form factors f and f, b) If Cu and Zn atoms randomly occupy every lattice site, then the form factor associated with every lattice site can be assumed to be the same, namely the average of the two form factors. Which Bragg spots will vanish in this case?