EN
III-V semiconducting compounds in the presence of a magnetic field are considered. The 14 x 14 effective hamiltonian in the frame of 5-level model is obtained. Directional dependence of selection rules are obtained. Shallow donor levels in the frame of spherical 3-level model are also considered. New trial functions suitable for a whole range of magnetic field are proposed. It is found that the energy as well as the variational function of each magnetodonor level is a continuous function of the magnetic field.