The Structure of Solids

· For the Cubic Lattice only, the dot product between the normal to a plane and a direction in the plane is zero: [h k l] . [u v w] = 0
· The cross product of the plane normals of intersecting planes gives the direction of the line of intersection: [uvw] = [h₁k₁l₁] x [h₂k₂l₂]
· [h₁k₁l₁] is normal to (h₁k₁l₁); [h₂k₂l₂] is normal to (h₂k₂l₂)