Orthogonality in Irreducible Inequivalent Representations

We come now to a very important point regarding representations. We will illustrate our arguments with the representation table (Table 13-13) for the Csv group. Notice the following features of that table  

If we choose the A representation, square all the numbers, and sum over all six symmetry operations, we get 6 as a result. 

If we do the same thing with the A2 representation, we get the same result. 

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