Akm[k_,m_]:=Piecewise[{{(Ea1u + Ea2u1 + Ea2u2 + 2*Eeu1 + 2*Eeu2)/7, k == 0 && m == 0}, {(-5*(5*Ea1u + Ea2u2 - Eeu1 - 5*Eeu2 + 4*Sqrt[5]*Ma2u + 2*Sqrt[5]*Meu))/28, k == 2 && m == 0}, {-((2*Sqrt[5]*Ea2u1 - 2*Sqrt[5]*Ea2u2 - Sqrt[5]*Eeu1 + Sqrt[5]*Eeu2 + Ma2u + 4*Meu)/Sqrt[14]), k == 4 && m == -3}, {(9*Ea1u + 14*Ea2u1 + 13*Ea2u2 - 34*Eeu1 - 2*Eeu2 - 4*Sqrt[5]*Ma2u - 16*Sqrt[5]*Meu)/14, k == 4 && m == 0}, {(2*Sqrt[5]*Ea2u1 - 2*Sqrt[5]*Ea2u2 - Sqrt[5]*Eeu1 + Sqrt[5]*Eeu2 + Ma2u + 4*Meu)/Sqrt[14], k == 4 && m == 3}, {(-13*Sqrt[11/21]*(9*Ea1u - 4*Ea2u1 - 5*Ea2u2 - 4*Sqrt[5]*Ma2u))/60, k == 6 && (m == -6 || m == 6)}, {(13*(4*Sqrt[5]*Ea2u1 - 4*Sqrt[5]*Ea2u2 + 9*Sqrt[5]*Eeu1 - 9*Sqrt[5]*Eeu2 + 2*Ma2u - 36*Meu))/(30*Sqrt[42]), k == 6 && m == -3}, {(-13*(3*Ea1u - 32*Ea2u1 - 25*Ea2u2 - 15*Eeu1 + 69*Eeu2 + 28*Sqrt[5]*Ma2u - 42*Sqrt[5]*Meu))/420, k == 6 && m == 0}, {(-13*(4*Sqrt[5]*Ea2u1 - 4*Sqrt[5]*Ea2u2 + 9*Sqrt[5]*Eeu1 - 9*Sqrt[5]*Eeu2 + 2*Ma2u - 36*Meu))/(30*Sqrt[42]), k == 6 && m == 3}}, 0]