Akm[k_,m_]:=Piecewise[{{(Ea + 2*(Ee1 + Ee2a + Ee2b))/7, k == 0 && m == 0}, {0, (k != 6 && ((k != 2 && k != 4) || m != 0)) || (m != -5 && m != 0 && m != 5)}, {(5*(2*Ea + 3*Ee1 - 5*Ee2b))/14, k == 2 && m == 0}, {(3*(3*Ea + Ee1 - 7*Ee2a + 3*Ee2b))/7, k == 4 && m == 0}, {((13*I)/5)*Sqrt[33/14]*(Me2Im + I*Me2Re), k == 6 && m == -5}, {(13*(10*Ea - 15*Ee1 + 6*Ee2a - Ee2b))/70, k == 6 && m == 0}}, (13*Sqrt[33/14]*(I*Me2Im + Me2Re))/5]