Matrix t2*K(2) in Subspace 57 with Dimension 4

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

(-15*t*U)/2 Sqrt[3/2]*t*U 0 -(Sqrt[3]*t*U)
Sqrt[3/2]*t*U -6*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 -6*t*U