Atomic structure and energetics of adsorbed water on the NaCl(001) surface

We have studied the structure and energetics of adsorbed water on the NaCl(001) surface using density-functional calculations within the generalized gradient approximation. We predict a new adsorption structure for the c(4x2) water bilayer which is energetically favored over the previous puckered hexagonal c(4x2) structure. Our calculations show that the 1x1 monolayer structure (wherein every water molecule binds to each surface cation) is metastable, thereby suggesting that the 1x1 structure would be transformed to the more stable c(4x2) structure which has an increased H-bond interactions between water molecules.