Could someone give me a brief explanation of how to label crystal planes? For example, labeling the back plane of a fcc crystal? I know that you take the axial intercepts, take their inverse, and come up with the miller indices, but certain planes (like the back plane or the left side plane) are difficult to label since they do not intersect the axis at a single point. similary, how would you then label a direction (such as a slip direction) who does not start at the origin. For example, labeling the burger vector in the slip plane (0001) <-- (I understand how to label this plane) how would I label the 3 burger vectors?