Materials Data on NaLaTa2O7 by Materials Project
NaLaTa2O7 crystallizes in the tetragonal I-4m2 space group. The structure is three-dimensional. Na1+ is bonded to four equivalent O2- atoms to form corner-sharing NaO4 tetrahedra. All Na–O bond lengths are 2.39 Å. La3+ is bonded to twelve O2- atoms to form a mixture of corner and face-sharing LaO12 cuboctahedra. There are eight shorter (2.69 Å) and four longer (2.78 Å) La–O bond lengths. Ta5+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ta–O bond distances ranging from 1.81–2.26 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a trigonal planar geometry to two equivalent Na1+ and one Ta5+ atom. In the second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent La3+ and two equivalent Ta5+ atoms. In the third O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent La3+ and two equivalent Ta5+ atoms. In the fourth O2- site, O2- is bonded to four equivalent La3+ and two equivalent Ta5+ atoms to form a mixture of distorted corner and edge-sharing OLa4Ta2 octahedra. The corner-sharing octahedral tilt angles are 0°.