THEORY OF THE STRUCTURAL AND ELECTRONIC-PROPERTIES OF ALPHA-GA(001) AND (010) SURFACES

We present a comprehensive study of the (001) and (010) surfaces of al pha-Ga via ab-initio local density calculations. Based on this it is p redicted 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, w e present the calculation of the band structure. Features related to t he presence or absence of reconstruction are pointed out. A comparison with existing scanning tunneling microscope data is given.