Comparative theory of missing-row reconstructions: Pt{1 1 0}, Pt{2 1 1} and Pt{3 1 1}

First principles pseudopotential density functional calculations have been performed to ascertain the surface energy difference between (1×1) and missing-row (1×2) reconstructions on the Pt{1 1 0}, Pt{2 1 1} and Pt{3 1 1} surfaces. The missing-row reconstruction is found to be favourable on the {1 1 0} surface, with a restructuring energy of 0.10 eV per (1×1) cell, and unfavourable on the {2 1 1} surface, as expected. The previously proposed missing-row reconstruction on the {3 1 1} surface is found to be favourable, with a reconstruction energy of 0.02 eV per (1×1) cell, in good agreement with recent calorimetric measurements.