Comparative study ofab initioand 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 ES(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 ES(110)∕ES(111) and ES(100)∕ES(111) are very close. The calculation of surface energy of reconstructed (1×2) Pt(110) confirms that this face undergoes a missing-row reconstruction and the corresponding 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)×(1̄11) vicinal surface and found a similar agreement for the LDOS.