Matrix t*K(1) in Subspace 135 with Dimension 12

(K(1) is the first-order Grosse operator)

((I/2)*t)/Sqrt[3] ((7 - (5*I)*Sqrt[3])*U)/12 0 ((-9*I - Sqrt[3])*t)/12 (-1 - I/Sqrt[3])*t -((3*I + Sqrt[3])*U)/6 0 (-1/4 - ((3*I)/4)*Sqrt[3])*t (1/Sqrt[2] - I/Sqrt[6])*t -(Sqrt[2]*(1 + I*Sqrt[3])*U)/3 (I - 1/(2*Sqrt[3]))*t -((3*I + Sqrt[3])*U)/12
((-7 - (5*I)*Sqrt[3])*U)/12 ((I/2)*t)/Sqrt[3] ((-3*I)/2 + 1/Sqrt[3])*t 0 0 (-I - 1/Sqrt[3])*t t/2 0 ((-I/3)*(-I + Sqrt[3])*U)/Sqrt[2] (1/Sqrt[2] - I/Sqrt[6])*t -((-3*I + Sqrt[3])*U)/4 (I/2 + 1/Sqrt[3])*t
0 ((-3*I)/2 - 1/Sqrt[3])*t (-I/2)*Sqrt[3]*t (U + (3*I)*Sqrt[3]*U)/4 0 -t -(Sqrt[3]*t)/2 ((-3*I + Sqrt[3])*U)/4 0 Sqrt[2/3]*t 0 (1 + (I/2)*Sqrt[3])*t
((-9*I + Sqrt[3])*t)/12 0 ((-1 + (3*I)*Sqrt[3])*U)/4 (I/2)*Sqrt[3]*t 0 0 -((3*I + Sqrt[3])*U)/4 ((-3*I)/2)*t ((-I)/Sqrt[2] + 1/Sqrt[6])*t 0 (-I/4)*(-I + Sqrt[3])*t 0
(1 - I/Sqrt[3])*t 0 0 0 0 0 0 0 I*Sqrt[2/3]*t 0 (I - Sqrt[3])*t 0
((-3*I + Sqrt[3])*U)/6 (-I + 1/Sqrt[3])*t t 0 0 0 Sqrt[3]*t 0 -((3*I + Sqrt[3])*U)/(3*Sqrt[2]) ((-I)/Sqrt[2] + 1/Sqrt[6])*t (U - I*Sqrt[3]*U)/2 0
0 -t/2 (Sqrt[3]*t)/2 ((-3*I + Sqrt[3])*U)/4 0 -(Sqrt[3]*t) (-I/2)*Sqrt[3]*t ((3 + I*Sqrt[3])*U)/4 0 -(Sqrt[2]*t) 0 -(Sqrt[3]*t)/2
((1 - (3*I)*Sqrt[3])*t)/4 0 -((3*I + Sqrt[3])*U)/4 ((-3*I)/2)*t 0 0 (I/4)*(3*I + Sqrt[3])*U (-I/2)*Sqrt[3]*t ((1 - I*Sqrt[3])*t)/Sqrt[2] 0 ((-3*I - Sqrt[3])*t)/4 0
(-(1/Sqrt[2]) - I/Sqrt[6])*t (Sqrt[2]*U - I*Sqrt[6]*U)/6 0 -((3*I + Sqrt[3])*t)/(3*Sqrt[2]) I*Sqrt[2/3]*t ((-3*I + Sqrt[3])*U)/(3*Sqrt[2]) 0 ((-1 - I*Sqrt[3])*t)/Sqrt[2] (I*t)/Sqrt[3] (-I/6)*(-5*I + Sqrt[3])*U ((-I)/Sqrt[2] + 1/Sqrt[6])*t -((-3*I + Sqrt[3])*U)/(3*Sqrt[2])
(Sqrt[2]*(1 - I*Sqrt[3])*U)/3 (-(1/Sqrt[2]) - I/Sqrt[6])*t -(Sqrt[2/3]*t) 0 0 -((3*I + Sqrt[3])*t)/(3*Sqrt[2]) Sqrt[2]*t 0 ((5 - I*Sqrt[3])*U)/6 (I*t)/Sqrt[3] 0 ((-I)/Sqrt[2] + 1/Sqrt[6])*t
((6*I + Sqrt[3])*t)/6 ((3*I + Sqrt[3])*U)/4 0 ((1 - I*Sqrt[3])*t)/4 (I + Sqrt[3])*t (-U - I*Sqrt[3]*U)/2 0 ((-3*I + Sqrt[3])*t)/4 -((3*I + Sqrt[3])*t)/(3*Sqrt[2]) 0 (-I/2)*Sqrt[3]*t ((3 - I*Sqrt[3])*U)/4
((-3*I + Sqrt[3])*U)/12 (I/2 - 1/Sqrt[3])*t (-1 + (I/2)*Sqrt[3])*t 0 0 0 (Sqrt[3]*t)/2 0 ((3*I + Sqrt[3])*U)/(3*Sqrt[2]) -((3*I + Sqrt[3])*t)/(3*Sqrt[2]) (-I/4)*(-3*I + Sqrt[3])*U (I/2)*Sqrt[3]*t