H-induced reconstructions on Pd(110)

The (110) surface of many transition metals undergoes reconstructions either on the clean substrate or induced by adsorbates. The reconstructions can be induced by a variety of strongly bound adsorbates, e.g., H, O, S, and alkali-metal atoms. In this work, H/Pd(110) is chosen as a prototype of such reconstructions. The pairing-row and missing-row reconstructions are studied in a wide range of coverages, $\ensuremath{\theta}=0.5--1.5\mathrm{ML},$ by using density-functional theory with the local-density approximation and the generalized gradient approximation. The driving force for the reconstructions is also analyzed in detail. The pairing-row reconstruction is driven essentially by the repulsion between the hydrogen atoms adsorbed in the same trough while the driving force for the missing-row reconstruction is the better adsorbate-substrate interaction on the reconstructed surface.