A theoretical study of the H-induced reconstructions of the Pd(110)surface

It is now established by experiments that the chemisorption of hydrogen on Pd(110) surface can induce reconstructions, Under different conditions of coverage and temperature, two types of reconstruction have been found: pairing-row and missing-row. Although the way in which the substrate reconstructs can be clearly deduced from experiments, the way in which H atoms are arranged on the reconstructed surfaces is not so well established. This is due to the difficulty of directly ''seeing'' H atoms by experimental methods, In this work, we report a systematic study of the reconstructions on Pd(110) by ab initio calculations based on density functional theory with local density approximation (LDA), generalized gradient approximation (GGA) and ultrasoft pseudopotentials. A variety of models are studied in detail. We show that only particular arrangements of H atoms can induce the surface reconstructions considered. The driving force for the reconstructions is analysed.