DOE OSTI2020
Sr3Nb is alpha bismuth trifluoride structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. there are two inequivalent Sr sites. In the first Sr site, Sr is bonded to four equivalent Sr and four equivalent Nb atoms to form distorted SrSr4Nb4 cuboctahedra that share corners with eight equivalent NbSr12 cuboctahedra, corners with sixteen SrSr4Nb4 cuboctahedra, edges with four equivalent NbSr12 cuboctahedra, edges with sixteen SrSr4Nb4 cuboctahedra, and faces with six equivalent SrSr4Nb4 cuboctahedra. All Sr–Sr bond lengths are 3.80 Å. All Sr–Nb bond lengths are 3.80 Å. In the second Sr site, Sr is bonded to eight equivalent Sr and four equivalent Nb atoms to form SrSr8Nb4 cuboctahedra that share corners with eight equivalent NbSr12 cuboctahedra, corners with twenty SrSr4Nb4 cuboctahedra, edges with sixteen SrSr4Nb4 cuboctahedra, faces with four equivalent SrSr8Nb4 cuboctahedra, and faces with six equivalent NbSr12 cuboctahedra. All Sr–Nb bond lengths are 3.92 Å. Nb is bonded to twelve Sr atoms to form NbSr12 cuboctahedra that share corners with four equivalent NbSr12 cuboctahedra, corners with twenty-four SrSr4Nb4 cuboctahedra, edges with eight equivalent SrSr4Nb4 cuboctahedra, edges with eight equivalent NbSr12 cuboctahedra, faces with four equivalent NbSr12 cuboctahedra, and faces with six equivalent SrSr8Nb4 cuboctahedra.