Comparative study of ab initio and tight-binding electronic structure calculations applied to platinum surfaces

We have applied the full-potential linearized augmented plane-wave (FLAPW) ab initio method and the spd tight-binding (TB) model to the calculations of the surface energies E S hkl and relaxations of the three low-index [(111), (100), (110)] surfaces of platinum. The two methods give similar results, and in particular the anisotropy ratios E_S(110) / E_S(111) and E_S(100) / E_S(111) are very close. The calculation of surface energy of reconstructed (1 x 2) Pt(110) confirms that this face undergoes a missing-row reconstruction and the corre-sponding structural parameters agree well with experiment. The local densities of states (LDOS) calculated by each of the methods on the flat surfaces are almost the same. We have also investigated the 6(111) x (1¯11) vicinal surface and found a similar agreement for the LDOS.