Matrix t2*K(2) in Subspace 50 with Dimension 12

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

(-17*t*U)/4 ((16*I)*(I + Sqrt[3])*t^2 + (-13 - I*Sqrt[3])*U^2)/24 ((-3*I - Sqrt[3])*t^2)/6 ((3*I)/4)*t*U (-I)*Sqrt[3]*t*U ((-I + Sqrt[3])*U^2)/4 (-I/2)*(-I + Sqrt[3])*t^2 (-I/4)*Sqrt[3]*t*U ((-1 - (3*I)*Sqrt[3])*t*U)/(2*Sqrt[2]) ((4*I)*(I + Sqrt[3])*t^2 + (-1 - I*Sqrt[3])*U^2)/(6*Sqrt[2]) -((3*I + 2*Sqrt[3])*t*U)/4 (8*(-3*I + Sqrt[3])*t^2 - (3*I + Sqrt[3])*U^2)/8
((-16*I)*(-I + Sqrt[3])*t^2 + I*(13*I + Sqrt[3])*U^2)/24 (-11*t*U)/4 ((3*I + 4*Sqrt[3])*t*U)/12 (-I + 1/Sqrt[3])*t^2 0 (-2*t*U)/Sqrt[3] (-3*t*U)/4 (-1 + I*Sqrt[3])*t^2 ((4 + (4*I)*Sqrt[3])*t^2 + (1 - I*Sqrt[3])*U^2)/(3*Sqrt[2]) ((-I/2)*(-I + Sqrt[3])*t*U)/Sqrt[2] (-16*(3*I + Sqrt[3])*t^2 + (-3*I + Sqrt[3])*U^2)/24 -((6*I + 5*Sqrt[3])*t*U)/12
((3*I - Sqrt[3])*t^2)/6 ((-3*I + 4*Sqrt[3])*t*U)/12 (-15*t*U)/4 (-24*t^2 + (3 - I*Sqrt[3])*U^2)/8 0 (-3*t*U)/2 ((-3*I)/4)*t*U (-8*Sqrt[3]*t^2 - (3*I + Sqrt[3])*U^2)/8 -(Sqrt[2]*(-3*I + Sqrt[3])*t^2)/3 ((-3*I + Sqrt[3])*t*U)/(3*Sqrt[2]) (I/2)*(I + Sqrt[3])*t^2 ((3*I)/4)*Sqrt[3]*t*U
((-3*I)/4)*t*U (I + 1/Sqrt[3])*t^2 (-24*t^2 + (3 + I*Sqrt[3])*U^2)/8 (-9*t*U)/4 0 0 (8*Sqrt[3]*t^2 - (-3*I + Sqrt[3])*U^2)/8 (Sqrt[3]*t*U)/4 (3*(I + Sqrt[3])*t*U)/(2*Sqrt[2]) -(Sqrt[2]*(3*I + Sqrt[3])*t^2)/3 (-3*t*U)/4 0
I*Sqrt[3]*t*U 0 0 0 -5*t*U (2*I - 2*Sqrt[3])*t^2 0 0 (-3*t*U)/Sqrt[2] 0 (-I)*t*U 0
((I + Sqrt[3])*U^2)/4 (-2*t*U)/Sqrt[3] (-3*t*U)/2 0 -2*(I + Sqrt[3])*t^2 -5*t*U (Sqrt[3]*t*U)/2 0 -((I + Sqrt[3])*U^2)/(2*Sqrt[2]) -((-9*I + Sqrt[3])*t*U)/(6*Sqrt[2]) ((3 + I*Sqrt[3])*U^2)/4 -(t*(U + I*Sqrt[3]*U))/2
(I/2)*(I + Sqrt[3])*t^2 (-3*t*U)/4 ((3*I)/4)*t*U (8*Sqrt[3]*t^2 - (3*I + Sqrt[3])*U^2)/8 0 (Sqrt[3]*t*U)/2 (-15*t*U)/4 (8*t^2 + U^2 - (3*I)*Sqrt[3]*U^2)/8 I*Sqrt[2]*(I + Sqrt[3])*t^2 0 ((3*I - Sqrt[3])*t^2)/2 (-3*Sqrt[3]*t*U)/4
(I/4)*Sqrt[3]*t*U (-1 - I*Sqrt[3])*t^2 (-8*Sqrt[3]*t^2 - (-3*I + Sqrt[3])*U^2)/8 (Sqrt[3]*t*U)/4 0 0 (8*t^2 + U^2 + (3*I)*Sqrt[3]*U^2)/8 (-15*t*U)/4 ((-I/2)*(-3*I + Sqrt[3])*t*U)/Sqrt[2] (Sqrt[2] + I*Sqrt[6])*t^2 (Sqrt[3]*t*U)/4 0
((-1 + (3*I)*Sqrt[3])*t*U)/(2*Sqrt[2]) ((4 - (4*I)*Sqrt[3])*t^2 + (1 + I*Sqrt[3])*U^2)/(3*Sqrt[2]) -(Sqrt[2]*(3*I + Sqrt[3])*t^2)/3 (3*(-I + Sqrt[3])*t*U)/(2*Sqrt[2]) (-3*t*U)/Sqrt[2] -((-I + Sqrt[3])*U^2)/(2*Sqrt[2]) (-Sqrt[2] - I*Sqrt[6])*t^2 ((I/2)*(3*I + Sqrt[3])*t*U)/Sqrt[2] (-5*t*U)/2 ((8 - (8*I)*Sqrt[3])*t^2 + (-7 - I*Sqrt[3])*U^2)/12 -((3*I + Sqrt[3])*t*U)/(2*Sqrt[2]) 0
((-4 - (4*I)*Sqrt[3])*t^2 + I*(I + Sqrt[3])*U^2)/(6*Sqrt[2]) ((I/2)*(I + Sqrt[3])*t*U)/Sqrt[2] ((3*I + Sqrt[3])*t*U)/(3*Sqrt[2]) -(Sqrt[2]*(-3*I + Sqrt[3])*t^2)/3 0 -((9*I + Sqrt[3])*t*U)/(6*Sqrt[2]) 0 (Sqrt[2] - I*Sqrt[6])*t^2 ((8 + (8*I)*Sqrt[3])*t^2 + I*(7*I + Sqrt[3])*U^2)/12 (-5*t*U)/2 (-4*(3*I + Sqrt[3])*t^2 + (-3*I + Sqrt[3])*U^2)/(6*Sqrt[2]) ((-3*I + 5*Sqrt[3])*t*U)/(6*Sqrt[2])
((3*I - 2*Sqrt[3])*t*U)/4 (-16*(-3*I + Sqrt[3])*t^2 + (3*I + Sqrt[3])*U^2)/24 (-I/2)*(-I + Sqrt[3])*t^2 (-3*t*U)/4 I*t*U ((3 - I*Sqrt[3])*U^2)/4 ((-3*I - Sqrt[3])*t^2)/2 (Sqrt[3]*t*U)/4 -((-3*I + Sqrt[3])*t*U)/(2*Sqrt[2]) (-4*(-3*I + Sqrt[3])*t^2 + (3*I + Sqrt[3])*U^2)/(6*Sqrt[2]) (-21*t*U)/4 ((8*I)*(I + Sqrt[3])*t^2 + (-5 - I*Sqrt[3])*U^2)/8
(8*(3*I + Sqrt[3])*t^2 - (-3*I + Sqrt[3])*U^2)/8 ((6*I - 5*Sqrt[3])*t*U)/12 ((-3*I)/4)*Sqrt[3]*t*U 0 0 (I/2)*(I + Sqrt[3])*t*U (-3*Sqrt[3]*t*U)/4 0 0 ((3*I + 5*Sqrt[3])*t*U)/(6*Sqrt[2]) ((-8 - (8*I)*Sqrt[3])*t^2 + I*(5*I + Sqrt[3])*U^2)/8 (-17*t*U)/4