Surface reconstructions and the local magnetic moments in Mn/GaAs(001) system

First principles calculations have been used to study the various surface reconstructions, local density of states of surface atoms, and the local magnetic moments of the Mn constituents in Mn/GaAs(001) surface. It is found that the Mn atoms will act as donors and donate as many electrons as required by the GaAs surface. The local magnetic moment of Mn being an important factor in surface magnetic properties can be deduced directly from the reconstruction by electron counting.