  The electronic and magnetic properties of bulk and (1 1 1) surfaces for MP
(M=K ans Rb) in rocksalt structure have been investigated by employing
first-principle calculations. The results reveal that the compounds are
half-metallic ferromagnets at the equilibrium lattice constants with large
half-metallic band gaps of 0.46 and 0.74 eV. The (111) surfaces of KP and RbP
keep their bulk half-metallic property. We study the stabilities of the bulk
compounds and their (1 1 1) surfaces as well.
