Materials Data on SrHfN2 by Materials Project
SrHfN2 crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional. Sr2+ is bonded to five equivalent N3- atoms to form a mixture of edge and corner-sharing SrN5 square pyramids. There are one shorter (2.55 Å) and four longer (2.87 Å) Sr–N bond lengths. Hf4+ is bonded in a 5-coordinate geometry to five N3- atoms. There are one shorter (2.01 Å) and four longer (2.16 Å) Hf–N bond lengths. There are two inequivalent N3- sites. In the first N3- site, N3- is bonded to four equivalent Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with four equivalent NSr5Hf octahedra, corners with four equivalent NHf4 trigonal pyramids, and edges with four equivalent NHf4 trigonal pyramids. The corner-sharing octahedral tilt angles are 69°. In the second N3- site, N3- is bonded to five equivalent Sr2+ and one Hf4+ atom to form distorted NSr5Hf octahedra that share corners with four equivalent NSr5Hf octahedra, corners with four equivalent NHf4 trigonal pyramids, and edges with eight equivalent NSr5Hf octahedra. The corner-sharing octahedral tilt angles are 8°.