Matrix t2*K(2) in Subspace 131 with Dimension 8

(K(2) is the second-order Grosse operator)

-5*t*U -((8*t^2 + U^2)/Sqrt[6]) t*U 0 (t*U)/Sqrt[2] 0 0 (-4*t^2 + U^2)/Sqrt[3]
-((8*t^2 + U^2)/Sqrt[6]) (-11*t*U)/2 0 (t*U)/Sqrt[6] (-4*t^2)/Sqrt[3] -(Sqrt[3]*t*U) U^2/Sqrt[3] Sqrt[2]*t*U
t*U 0 -6*t*U 4*t^2 (-3*t*U)/Sqrt[2] 0 -(Sqrt[2]*t*U) 0
0 (t*U)/Sqrt[6] 4*t^2 -4*t*U -(U^2/Sqrt[2]) 0 0 (2*t*U)/Sqrt[3]
(t*U)/Sqrt[2] (-4*t^2)/Sqrt[3] (-3*t*U)/Sqrt[2] -(U^2/Sqrt[2]) (-9*t*U)/2 U^2 t*U 4*Sqrt[2/3]*t^2
0 -(Sqrt[3]*t*U) 0 0 U^2 -6*t*U -4*t^2 0
0 U^2/Sqrt[3] -(Sqrt[2]*t*U) 0 t*U -4*t^2 -3*t*U -(Sqrt[2/3]*U^2)
(-4*t^2 + U^2)/Sqrt[3] Sqrt[2]*t*U 0 (2*t*U)/Sqrt[3] 4*Sqrt[2/3]*t^2 0 -(Sqrt[2/3]*U^2) -2*t*U