3- Calculate the separation of the (123) planes and the (246) planes of an orthorhombic cell with a = 0.82 nm, b = 0.94 nm, and c = 0.75 nm. ( 4 points) 4- Show d ( hkl) 2 TT G n where G =hb, +kb2 +/b3 (4 points) 5- For the fours, planes that are shown by arrows label their associated miller indices ( 8 points) a3 90% ? 90 hexagonal, four axis (a1,a2,a3,c) 120 a2 120 b al a