Akm[k_,m_]:=Piecewise[{{(Edx2y2dx2y2 + Edxydxy + Edxzdxz + Edyzdyz + Edz2dz2)/5, k == 0 && m == 0}, {0, (k != 2 && k != 4) || (k != 4 && m != -2 && m != -1 && m != 0 && m != 1 && m != 2) || (m != -4 && m != -3 && m != -2 && m != -1 && m != 0 && m != 1 && m != 2 && m != 3 && m != 4)}, {-(4*Edx2y2dz2 - Sqrt[3]*Edxzdxz - (2*I)*Sqrt[3]*Edyzdxz + Sqrt[3]*Edyzdyz + (4*I)*Edz2dxy)/(2*Sqrt[2]), k == 2 && m == -2}, {(Sqrt[3]*Edx2y2dxz - I*Sqrt[3]*Edx2y2dyz + I*Sqrt[3]*Edxzdxy + Sqrt[3]*Edyzdxy + Edz2dxz + I*Edz2dyz)/Sqrt[2], k == 2 && m == -1}, {(-2*Edx2y2dx2y2 - 2*Edxydxy + Edxzdxz + Edyzdyz + 2*Edz2dz2)/2, k == 2 && m == 0}, {-((Sqrt[3]*Edx2y2dxz + I*Sqrt[3]*Edx2y2dyz - I*Sqrt[3]*Edxzdxy + Sqrt[3]*Edyzdxy + Edz2dxz - I*Edz2dyz)/Sqrt[2]), k == 2 && m == 1}, {-(4*Edx2y2dz2 - Sqrt[3]*Edxzdxz + (2*I)*Sqrt[3]*Edyzdxz + Sqrt[3]*Edyzdyz - (4*I)*Edz2dxy)/(2*Sqrt[2]), k == 2 && m == 2}, {(3*Sqrt[7/10]*(Edx2y2dx2y2 + (2*I)*Edx2y2dxy - Edxydxy))/2, k == 4 && m == -4}, {(3*Sqrt[7/5]*(Edx2y2dxz + I*(Edx2y2dyz + Edxzdxy + I*Edyzdxy)))/2, k == 4 && m == -3}, {(3*(Sqrt[3]*Edx2y2dz2 + Edxzdxz + (2*I)*Edyzdxz - Edyzdyz + I*Sqrt[3]*Edz2dxy))/Sqrt[10], k == 4 && m == -2}, {(-3*(Edx2y2dxz - I*Edx2y2dyz + I*Edxzdxy + Edyzdxy - 2*Sqrt[3]*Edz2dxz - (2*I)*Sqrt[3]*Edz2dyz))/(2*Sqrt[5]), k == 4 && m == -1}, {(3*(Edx2y2dx2y2 + Edxydxy - 4*Edxzdxz - 4*Edyzdyz + 6*Edz2dz2))/10, k == 4 && m == 0}, {(3*(Edx2y2dxz + I*Edx2y2dyz - I*Edxzdxy + Edyzdxy - 2*Sqrt[3]*Edz2dxz + (2*I)*Sqrt[3]*Edz2dyz))/(2*Sqrt[5]), k == 4 && m == 1}, {(3*(Sqrt[3]*Edx2y2dz2 + Edxzdxz - (2*I)*Edyzdxz - Edyzdyz - I*Sqrt[3]*Edz2dxy))/Sqrt[10], k == 4 && m == 2}, {(3*Sqrt[7/5]*(-Edx2y2dxz + I*Edx2y2dyz + I*Edxzdxy + Edyzdxy))/2, k == 4 && m == 3}}, (3*Sqrt[7/10]*(Edx2y2dx2y2 - (2*I)*Edx2y2dxy - Edxydxy))/2]