Materials Data on BaHfN2 by Materials Project
BaHfN2 crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional. Ba2+ is bonded to five equivalent N3- atoms to form BaN5 square pyramids that share corners with four equivalent BaN5 square pyramids, corners with five equivalent HfN5 trigonal bipyramids, and edges with eight equivalent BaN5 square pyramids. There are one shorter (2.82 Å) and four longer (2.95 Å) Ba–N bond lengths. Hf4+ is bonded to five N3- atoms to form distorted HfN5 trigonal bipyramids that share corners with five equivalent BaN5 square pyramids, corners with four equivalent HfN5 trigonal bipyramids, and edges with four equivalent HfN5 trigonal bipyramids. There are one shorter (1.99 Å) and four longer (2.20 Å) Hf–N bond lengths. There are two inequivalent N3- sites. In the first N3- site, N3- is bonded to five equivalent Ba2+ and one Hf4+ atom to form distorted NBa5Hf octahedra that share corners with four equivalent NBa5Hf octahedra, corners with four equivalent NHf4 trigonal pyramids, and edges with eight equivalent NBa5Hf octahedra. The corner-sharing octahedral tilt angles are 9°. In the second N3- site, N3- is bonded to four equivalent Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with four equivalent NBa5Hf octahedra, corners with four equivalent NHf4 trigonal pyramids, and edges with four equivalent NHf4 trigonal pyramids. The corner-sharing octahedral tilt angles are 71°.