Theory of the structural and electronic properties of α-Ga(001) and (010) surfaces

We present a comprehensive study of the (001) and (010) surfaces of {α}-Ga via ab-initio local density calculations. Based on this it is predicted that the (001) surface should be covered in the ground state by two layers of epitaxial GaIII, a denser phase stable in the bulk at high pressures and temperatures. On the contrary the ground state of the (010) surface is found to be unreconstructed. For both surfaces, we present the calculation of the band structure. Features related to the presence or absence of reconstruction are pointed out. A comparison with existing scanning tunneling microscope data is given.