Materials Data on MgNb3 by Materials Project
MgNb3 is alpha bismuth trifluoride structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. Mg is bonded in a distorted body-centered cubic geometry to fourteen Nb atoms. There are eight shorter (2.90 Å) and six longer (3.34 Å) Mg–Nb bond lengths. There are two inequivalent Nb sites. In the first Nb site, Nb is bonded in a distorted body-centered cubic geometry to four equivalent Mg and four equivalent Nb atoms. All Nb–Nb bond lengths are 2.90 Å. In the second Nb site, Nb is bonded in a 8-coordinate geometry to six equivalent Mg and eight equivalent Nb atoms.