Matrix t2*K(2) in Subspace 110 with Dimension 12

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

(-21*t*U)/4 t^2*(4 - U^2/(4*t^2)) 0 -(Sqrt[3]*t*U) -((-3*I + Sqrt[3])*t*U)/(2*Sqrt[2]) 0 (3*(I + Sqrt[3])*t*U)/(4*Sqrt[2]) 0 0 -((-3*I + Sqrt[3])*t*U)/(4*Sqrt[2]) -(Sqrt[3]*U^2)/4 ((3*I)/4)*t*U
t^2*(4 - U^2/(4*t^2)) (-27*t*U)/4 0 0 0 (((-3*I)/2)*t*U)/Sqrt[2] 0 -((3*I + Sqrt[3])*t*U)/(4*Sqrt[2]) (Sqrt[3/2]*t*U)/2 0 -(Sqrt[3]*t*U)/4 ((-3*I)/4)*U^2
0 0 -4*t*U (2 + (2*I)*Sqrt[3])*t^2 0 ((3 - I*Sqrt[3])*t*U)/(2*Sqrt[2]) 0 ((2 - I*Sqrt[3])*t*U)/Sqrt[2] ((2 + I*Sqrt[3])*t*U)/Sqrt[2] 0 0 0
-(Sqrt[3]*t*U) 0 (2 - (2*I)*Sqrt[3])*t^2 -4*t*U (I*(I + Sqrt[3])*t*U)/Sqrt[2] (-I)*Sqrt[3/2]*U^2 ((3 + I*Sqrt[3])*t*U)/(2*Sqrt[2]) 0 0 0 0 0
-((3*I + Sqrt[3])*t*U)/(2*Sqrt[2]) 0 0 ((-1 - I*Sqrt[3])*t*U)/Sqrt[2] (-9*t*U)/2 ((3 - I*Sqrt[3])*U^2)/4 0 -2*t^2 -2*t^2 t*U (-Sqrt[2] - I*Sqrt[6])*t^2 ((I/2)*(3*I + Sqrt[3])*t*U)/Sqrt[2]
0 (((3*I)/2)*t*U)/Sqrt[2] ((3 + I*Sqrt[3])*t*U)/(2*Sqrt[2]) I*Sqrt[3/2]*U^2 ((3 + I*Sqrt[3])*U^2)/4 -5*t*U (2 - (2*I)*Sqrt[3])*t^2 ((-1 + (3*I)*Sqrt[3])*t*U)/4 ((2 - I*Sqrt[3])*t*U)/2 0 ((3*I)/2)*Sqrt[3/2]*t*U 0
(3*(-I + Sqrt[3])*t*U)/(4*Sqrt[2]) 0 0 ((3 - I*Sqrt[3])*t*U)/(2*Sqrt[2]) 0 (2 + (2*I)*Sqrt[3])*t^2 -6*t*U (-I/4)*(-I + Sqrt[3])*U^2 ((1 - I*Sqrt[3])*U^2)/4 (I/2)*Sqrt[3]*t*U 0 (t*(Sqrt[2]*U + I*Sqrt[6]*U))/8
0 -((-3*I + Sqrt[3])*t*U)/(4*Sqrt[2]) ((2 + I*Sqrt[3])*t*U)/Sqrt[2] 0 -2*t^2 -(t*(U + (3*I)*Sqrt[3]*U))/4 (I/4)*(I + Sqrt[3])*U^2 -5*t*U ((-1 + (5*I)*Sqrt[3])*t*U)/4 (-8*t^2 - U^2 - I*Sqrt[3]*U^2)/4 (((3*I)/4)*(I + Sqrt[3])*t*U)/Sqrt[2] (Sqrt[2] + I*Sqrt[6])*t^2
0 (Sqrt[3/2]*t*U)/2 ((2 - I*Sqrt[3])*t*U)/Sqrt[2] 0 -2*t^2 ((2 + I*Sqrt[3])*t*U)/2 ((1 + I*Sqrt[3])*U^2)/4 -(t*(U + (5*I)*Sqrt[3]*U))/4 -5*t*U (-8*t^2 - U^2 + I*Sqrt[3]*U^2)/4 (3*t*U)/(2*Sqrt[2]) (-Sqrt[2] - I*Sqrt[6])*t^2
-((3*I + Sqrt[3])*t*U)/(4*Sqrt[2]) 0 0 0 t*U 0 (-I/2)*Sqrt[3]*t*U (-8*t^2 - U^2 + I*Sqrt[3]*U^2)/4 (-8*t^2 - U^2 - I*Sqrt[3]*U^2)/4 -7*t*U (Sqrt[2] + I*Sqrt[6])*t^2 ((I/4)*(3*I + Sqrt[3])*t*U)/Sqrt[2]
-(Sqrt[3]*U^2)/4 -(Sqrt[3]*t*U)/4 0 0 I*Sqrt[2]*(I + Sqrt[3])*t^2 ((-3*I)/2)*Sqrt[3/2]*t*U 0 (((-3*I)/4)*(-I + Sqrt[3])*t*U)/Sqrt[2] (3*t*U)/(2*Sqrt[2]) (Sqrt[2] - I*Sqrt[6])*t^2 (-21*t*U)/4 (I/4)*Sqrt[3]*U^2
((-3*I)/4)*t*U ((3*I)/4)*U^2 0 0 ((-I/2)*(-3*I + Sqrt[3])*t*U)/Sqrt[2] 0 (t*(Sqrt[2]*U - I*Sqrt[6]*U))/8 (Sqrt[2] - I*Sqrt[6])*t^2 I*Sqrt[2]*(I + Sqrt[3])*t^2 ((-I/4)*(-3*I + Sqrt[3])*t*U)/Sqrt[2] (-I/4)*Sqrt[3]*U^2 (-21*t*U)/4