DOE OSTI2020
In12Se19N2 crystallizes in the triclinic P-1 space group. The structure is three-dimensional and consists of two ammonia molecules and one In12Se19 framework. In the In12Se19 framework, there are six inequivalent In3+ sites. In the first In3+ site, In3+ is bonded to four Se2- atoms to form InSe4 tetrahedra that share corners with two InSe4 tetrahedra and corners with four InSe5 trigonal pyramids. There are a spread of In–Se bond distances ranging from 2.57–2.71 Å. In the second In3+ site, In3+ is bonded to four Se2- atoms to form InSe4 tetrahedra that share corners with two InSe4 tetrahedra and corners with four InSe5 trigonal pyramids. There are a spread of In–Se bond distances ranging from 2.58–2.71 Å. In the third In3+ site, In3+ is bonded to four Se2- atoms to form InSe4 tetrahedra that share corners with two InSe4 tetrahedra and corners with four InSe5 trigonal pyramids. There are a spread of In–Se bond distances ranging from 2.58–2.71 Å. In the fourth In3+ site, In3+ is bonded to five Se2- atoms to form distorted InSe5 trigonal pyramids that share corners with four InSe4 tetrahedra, corners with three InSe5 trigonal pyramids, and edges with three InSe5 trigonal pyramids. There are a spread of In–Se bond distances ranging from 2.61–3.48 Å. In the fifth In3+ site, In3+ is bonded to five Se2- atoms to form InSe5 trigonal pyramids that share corners with four InSe4 tetrahedra, corners with three InSe5 trigonal pyramids, and edges with three InSe5 trigonal pyramids. There are a spread of In–Se bond distances ranging from 2.61–3.58 Å. In the sixth In3+ site, In3+ is bonded to five Se2- atoms to form distorted InSe5 trigonal pyramids that share corners with four InSe4 tetrahedra, corners with three InSe5 trigonal pyramids, and edges with three InSe5 trigonal pyramids. There are a spread of In–Se bond distances ranging from 2.61–3.52 Å. There are ten inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a distorted T-shaped geometry to three In3+ atoms. In the second Se2- site, Se2- is bonded in a distorted T-shaped geometry to three In3+ atoms. In the third Se2- site, Se2- is bonded in a distorted T-shaped geometry to three In3+ atoms. In the fourth Se2- site, Se2- is bonded in a 2-coordinate geometry to six In3+ atoms. In the fifth Se2- site, Se2- is bonded in a trigonal non-coplanar geometry to three In3+ atoms. In the sixth Se2- site, Se2- is bonded in a trigonal non-coplanar geometry to three In3+ atoms. In the seventh Se2- site, Se2- is bonded in a trigonal non-coplanar geometry to three In3+ atoms. In the eighth Se2- site, Se2- is bonded in a water-like geometry to two In3+ atoms. In the ninth Se2- site, Se2- is bonded in a water-like geometry to two In3+ atoms. In the tenth Se2- site, Se2- is bonded in a water-like geometry to two In3+ atoms.