Chapter 3 : 3. 14, 3. 15, reading: pp. 70-76. Crystallographic planes a y b x: miller indices. Reciprocals of the (three) axial intercepts for a plane, clear fractions. All parallel planes have same miller indices: algorithm. 2 read off intercepts of plane with axes in terms of a, b, c. 3 take reciprocals of intercepts: reduce to smallest integer values, enclose in parentheses, no commas, i. e. , (hkl) Example: determine the miller indices for the plane shown to the right. c a x (0,0,0) b y. The plane of interest must not pass through the origin. If the plane does pass through the given origin then shift the origin to another corner of the unit cell. Step 4: determine the reciprocals of the planar intercepts: if necessary, multiply or divide the reciprocals determined in step 3 by a common factor to reduce to the smallest set of integers.