A combined EXAFS and DFT study of the Ni2+ environment in dehydrated Ni/NaX

The location of the divalent nickel cation exchanged in low amount in dehydrated NaX is identified by a combination of experimental (XAS) and theoretical (DFT) approaches. The Ni–O and Ni–T distances as well as the coordination numbers evaluated from experiments are in good agreement with the predicted models obtained from calculations. After dehydration, the migration of Ni2+ towards the hexagonal prism is confirmed and three distinct possible nickel sites are predicted. The results show the tendency of Ni2+ to get closer to the most basic framework oxygen atoms.