Electronic Structure of Monomeric Water Adsorption on Ni{111}: Beyond the General Model

The adsorption of an H 2 O molecule on Ni{111} has been investigated by density functional theory (DFT) calculations. In addition to the consensus between previously reported experimental data and our DFT results arrived at via the surface relaxation pattern, the electron work function and energy levels of a free H 2 O, as well as the adsorption energy, we have further presented a previously unrecognized electronic picture for the stable on-top adsorption, by analysis of projected density of states. We have provided clear evidence that the Ni 3p orbitals (p z and p y ), specifically the hybrid orbitals: 3p z −2p z, 3p y −2p z, 3p z −2p y, and 3p y −2p y, play crucial roles in the water bonding at the surface. Our results thus offer a new and inclusive understanding of the electronic nature, which is beyond the conventional model of 3a 1 −3p z and 3a 1 −3p y interactions.