Matrix H in Subspace 97 with Dimension 14

H is the Hamiltonian. Here we set µ=0. For grand-canonical calculations add -6µ to the main diagonal.
2*U -t ((-1 - I*Sqrt[3])*t)/Sqrt[2] 0 0 0 0 t 0 0 (I/2)*(I + Sqrt[3])*t 0 (t + I*Sqrt[3]*t)/2 0
-t 2*U 0 0 0 0 0 0 0 Sqrt[2]*t 0 (t + I*Sqrt[3]*t)/2 0 (I/2)*(3*I + Sqrt[3])*t
(I*(I + Sqrt[3])*t)/Sqrt[2] 0 2*U 0 0 0 0 0 Sqrt[2]*t 0 0 -(Sqrt[2]*t) 0 0
0 0 0 2*U -t 0 (-I/2)*(-I + Sqrt[3])*t 0 0 0 t 0 t 0
0 0 0 -t 2*U -t 0 0 0 0 0 ((3 + I*Sqrt[3])*t)/2 0 (t - I*Sqrt[3]*t)/2
0 0 0 0 -t 2*U -t t 0 0 -t 0 0 0
0 0 0 (I/2)*(I + Sqrt[3])*t 0 -t 2*U 0 0 ((1 - I*Sqrt[3])*t)/Sqrt[2] 0 0 0 0
t 0 0 0 0 t 0 U -t 0 0 0 0 (t + I*Sqrt[3]*t)/2
0 0 Sqrt[2]*t 0 0 0 0 -t U 0 0 0 (I/2)*(I + Sqrt[3])*t 0
0 Sqrt[2]*t 0 0 0 0 ((1 + I*Sqrt[3])*t)/Sqrt[2] 0 0 U (I*(I + Sqrt[3])*t)/Sqrt[2] 0 0 0
(-I/2)*(-I + Sqrt[3])*t 0 0 t 0 -t 0 0 0 ((-1 - I*Sqrt[3])*t)/Sqrt[2] U (I/2)*(I + Sqrt[3])*t 0 0
0 (t - I*Sqrt[3]*t)/2 -(Sqrt[2]*t) 0 ((3 - I*Sqrt[3])*t)/2 0 0 0 0 0 (-I/2)*(-I + Sqrt[3])*t U 0 0
(t - I*Sqrt[3]*t)/2 0 0 t 0 0 0 0 (-I/2)*(-I + Sqrt[3])*t 0 0 0 U -t
0 (-I/2)*(-3*I + Sqrt[3])*t 0 0 (t + I*Sqrt[3]*t)/2 0 0 (t - I*Sqrt[3]*t)/2 0 0 0 0 -t U