2. Point Coordinates, Crystallographic Directions and Crystallographic Planes (20 points) A. For the b-Sn structure in Fig. 1, identify the point coordinates of each of the 4 atoms in the unit cell. (5 points) B. A vector in a cubic unit cell passes from a point to a point Calculate the direction indices of this vector. Also list all directions that are equivalent to this vector in the cubic unit cell. (5 points) C. Determine the Miller indices for planes A and B in Fig. 2. (5 points)