Dialog Box: Align Face or Vector [ Rotation Menu]
<Standard Mode - see also Align Face or Vector (Cartesian)>
This will rotate a specified face (hkl) to lie flat in the screen or paper (face-normal parallel to x observer), or a vector (uvw) to be perpendicular to the screen or paper. To align a face, it is also necessary to specify a vector lying in the face which will be vertical in the screen or paper (z direction). Conversely, to align a vector, it is necessary to specify a face, containing the vector, whose normal will be vertical. If a vector [uvw] lies in a face (hkl), the indices satisfy the condition hu + kv + lw = 0. If clinographic viewing is in effect, it is turned off when the face is aligned, to simplify any subsequent rotations.
You can elect to use a default alignment vector or face. The default vector will be the intersection of the face (hkl) with the face (100), whose indices are given by the cross product (hkl)x(100). If the face (hkl) is (100), the default alignment vector will be the vector [001]. For aligning a vector the algebra is just the same, with interchange of face and vector.