Matrix t*K(1) in Subspace 48 with Dimension 3

(K(1) is the first-order Grosse operator)

I*Sqrt[3]*t ((-3 - I*Sqrt[3])*t)/Sqrt[2] U
((3 - I*Sqrt[3])*t)/Sqrt[2] 0 ((1 + I*Sqrt[3])*U)/Sqrt[2]
-U (I*(I + Sqrt[3])*U)/Sqrt[2] (-I)*Sqrt[3]*t