{{1/sqrt(3), 0, -sqrt(2/3)}, {0, 1, 0}, {sqrt(2/3), 0, 1/(sqrt(3))}}.{{5, 0, 0}, {0, 5, 0}, {0, 0, -1}}.{{1/sqrt(3), 0, sqrt(2/3)}, {0, 1, 0}, {-sqrt(2/3), 0, 1/(sqrt(3))}}

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