[[2/3,2/3,-1/3],[1/sqrt(2),-1/sqrt(2),0],[1/sqrt(18),1/sqrt(18),4/sqrt(18)]]*[[2,-4,2],[-4,2,2],[2,2,5]]*transpose([[2/3,2/3,-1/3],[1/sqrt(2),-1/sqrt(2),0],[1/sqrt(18),1/sqrt(18),4/sqrt(18)]])

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