A = {{0.872, 0.218, 0.253}, {0.218, 0.628, -0.431}, {0.253, -0.431,
   0.500}}

{{0.872, 0.218, 0.253}, {0.218, 0.628, -0.431}, {0.253, -0.431, 0.5}}

A.A - A // MatrixForm

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