Structural and electronic properties of Ni₅Nb₃Zr ₅ clusters as a local structural unit of Ni-Nb-Zr glassy alloys

We calculate electronic states of fifty icosahedral Ni₅Nb ₃Zr₅ clusters and optimize their structures by first principles calculations within the generalized gradient approximation. Based on the energetic stability and the atomic configuration, we search for some candidates for the local structural units of Ni₃₆Nb ₂₄Zr₄₀ glassy alloys by comparing with the experimental data measured by the XAFS method. The Ni-centered icosahedral Ni ₅Nb₃Zr₅ clusters containing a Nb-triangle are proposed as the structural units, which in turn combine into local structures of the glassy alloy.