Matrix t2*K(2) in Subspace 14 with Dimension 3

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

-3*t*U ((I/2)*(3*I + Sqrt[3])*U^2)/Sqrt[2] (3*(1 - I*Sqrt[3])*t*U)/(2*Sqrt[2])
((-I/2)*(-3*I + Sqrt[3])*U^2)/Sqrt[2] (-3*t*U)/2 (I/4)*(3*I + Sqrt[3])*U^2
(3*(1 + I*Sqrt[3])*t*U)/(2*Sqrt[2]) (-I/4)*(-3*I + Sqrt[3])*U^2 (-9*t*U)/2