Akm[k_,m_]:=Piecewise[{{0, (k != 2 && k != 4) || (k != 4 && m != -2 && m != -1 && m != 1 && m != 2) || (m != -4 && m != -3 && m != -2 && m != -1 && m != 0 && m != 1 && m != 2 && m != 3 && m != 4)}, {(I/3)*Sqrt[5/14]*(3*Ma2u1 + 4*Meu2), k == 2 && m == -2}, {(1/3 + I/3)*Sqrt[5/14]*(3*Ma2u1 + 4*Meu2), k == 2 && m == -1}, {(-1/3 + I/3)*Sqrt[5/14]*(3*Ma2u1 + 4*Meu2), k == 2 && m == 1}, {(-I/3)*Sqrt[5/14]*(3*Ma2u1 + 4*Meu2), k == 2 && m == 2}, {-(Sqrt[3/10]*(2*Sqrt[5]*Ma2u1 - 15*Meu1 + Sqrt[5]*Meu2))/4, k == 4 && (m == -4 || m == 4)}, {(-1/2 + I/2)*Sqrt[3]*(Ma2u1 - Meu2), k == 4 && m == -3}, {I*Sqrt[6/7]*(Ma2u1 - Meu2), k == 4 && m == -2}, {(-1/2 - I/2)*Sqrt[3/7]*(Ma2u1 - Meu2), k == 4 && m == -1}, {-(Sqrt[21]*(2*Sqrt[5]*Ma2u1 - 15*Meu1 + Sqrt[5]*Meu2))/20, k == 4 && m == 0}, {(1/2 - I/2)*Sqrt[3/7]*(Ma2u1 - Meu2), k == 4 && m == 1}, {(-I)*Sqrt[6/7]*(Ma2u1 - Meu2), k == 4 && m == 2}}, (1/2 + I/2)*Sqrt[3]*(Ma2u1 - Meu2)]