Miller Indices

Miller Indices

Rules for Miller Indices: For example, if the x-, y-, and z- intercepts are 2, 1, and 3, the Miller indices are calculated as: Thus, the Miller indices are 3,6,2. If a plane is parallel to an axis, its intercept is at infinity and its Miller index is zero. A generic Miller index is denoted by (hkl).

If a plane has negative intercept, the negative number is denoted by a bar above the number. Never alter negative numbers. For example, do not divide -1, -1, -1 by -1 to get 1,1,1. This implies symmetry that the crystal may not have!

Some General Principles

Why Miller Indices?

Movie of aminated gif above. Click the pause button, then step through the planes