Matrix t2*K(2) in Subspace 62 with Dimension 4

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

(-3*t*U)/2 Sqrt[3/2]*t*U 0 -(Sqrt[3]*t*U)
Sqrt[3/2]*t*U -3*t*U U^2/Sqrt[2] 0
0 U^2/Sqrt[2] (-9*t*U)/2 -U^2
-(Sqrt[3]*t*U) 0 -U^2 -3*t*U