ABSTRACT
In the cubic system, a plane normal (pole) with indices hkl is parallel to a direction uvw when h = u , k = v , l = w $ h=u, k=v, l=w $ https://s3-euw1-ap-pe-df-pch-content-public-u.s3.eu-west-1.amazonaws.com/9781315114910/a1f6aa37-c8b0-4273-bc79-d03791cd487d/content/inline-math3_1.tif"/> ; thus the normal to (123) is parallel to [123]. This is generally not the case for less symmetrical systems. Figure 3.1 illustrates this for a two-dimensional unit cell in which b > a $ b>a $ https://s3-euw1-ap-pe-df-pch-content-public-u.s3.eu-west-1.amazonaws.com/9781315114910/a1f6aa37-c8b0-4273-bc79-d03791cd487d/content/inline-math3_2.tif"/> .
