First-principles calculations on the structures and electronic properties of the TMW2On (TM = Mn-Ni, n=1-6) clusters

Transition metals can enhance the electronic attributes of tungsten oxides. In this study, we focused on W2On (n = 1-6) clusters as a representative examples of tungsten oxide clusters with varying oxygen concentrations. The structures and electronic properties of the TMWOn (TM = Mn-Ni) clusters have been calculated using first-principles. The ground-state TMWOn clusters share some structural similarities with the ground-state W2On (n = 1-6) clusters. The W-O bonds of the TMWO2 (TM = Fe-Ni) clusters are significantly distorted into a triangular structure. The NiWOn (n = 1-2) and CoWOn (n = 3-5) clusters display greater thermodynamic stability than other TMWOn clusters. Among the TMWOn clusters, the W2O4, W2O6, MnWO, MnWO3, MnWO6, FeWO, FeWO4, FeWO6, CoWO, CoWO6, NiWO2, NiWO5 clusters are more kinetically stable. Furthermore, the amount of charge transfer between the TM atoms and W2On clusters increases from 0.050 |e| to 1.066 |e| as the number of oxygen atoms increases. The 4s orbital electrons of the TM atoms for the TMWOn clusters are partially transferred to the neighboring O atoms.