Materials Data on Na3Mo15Se19 by Materials Project
Na3Mo15Se19 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 7-coordinate geometry to seven Se2- atoms. There are a spread of Na–Se bond distances ranging from 3.02–3.54 Å. In the second Na1+ site, Na1+ is bonded to six Se2- atoms to form distorted NaSe6 octahedra that share corners with eight MoSe5 square pyramids and edges with four MoSe5 square pyramids. There are a spread of Na–Se bond distances ranging from 2.74–3.08 Å. There are nine inequivalent Mo+2.33+ sites. In the first Mo+2.33+ site, Mo+2.33+ is bonded in a see-saw-like geometry to four Se2- atoms. There are one shorter (2.58 Å) and three longer (2.59 Å) Mo–Se bond lengths. In the second Mo+2.33+ site, Mo+2.33+ is bonded in a see-saw-like geometry to four Se2- atoms. There are one shorter (2.57 Å) and three longer (2.59 Å) Mo–Se bond lengths. In the third Mo+2.33+ site, Mo+2.33+ is bonded in a see-saw-like geometry to four Se2- atoms. There are a spread of Mo–Se bond distances ranging from 2.59–2.65 Å. In the fourth Mo+2.33+ site, Mo+2.33+ is bonded to five Se2- atoms to form MoSe5 square pyramids that share a cornercorner with one NaSe6 octahedra, corners with four MoSe5 square pyramids, and edges with three MoSe5 square pyramids. The corner-sharing octahedral tilt angles are 59°. There are a spread of Mo–Se bond distances ranging from 2.55–2.71 Å. In the fifth Mo+2.33+ site, Mo+2.33+ is bonded to five Se2- atoms to form MoSe5 square pyramids that share a cornercorner with one NaSe6 octahedra, corners with four MoSe5 square pyramids, and edges with three MoSe5 square pyramids. The corner-sharing octahedral tilt angles are 50°. There are a spread of Mo–Se bond distances ranging from 2.54–2.73 Å. In the sixth Mo+2.33+ site, Mo+2.33+ is bonded to five Se2- atoms to form MoSe5 square pyramids that share corners with four MoSe5 square pyramids, an edgeedge with one NaSe6 octahedra, and edges with three MoSe5 square pyramids. There are a spread of Mo–Se bond distances ranging from 2.54–2.75 Å. In the seventh Mo+2.33+ site, Mo+2.33+ is bonded to five Se2- atoms to form MoSe5 square pyramids that share a cornercorner with one NaSe6 octahedra, corners with three MoSe5 square pyramids, and edges with five MoSe5 square pyramids. The corner-sharing octahedral tilt angles are 53°. There are a spread of Mo–Se bond distances ranging from 2.53–2.71 Å. In the eighth Mo+2.33+ site, Mo+2.33+ is bonded to five Se2- atoms to form MoSe5 square pyramids that share a cornercorner with one NaSe6 octahedra, corners with three MoSe5 square pyramids, and edges with five MoSe5 square pyramids. The corner-sharing octahedral tilt angles are 35°. There are a spread of Mo–Se bond distances ranging from 2.51–2.70 Å. In the ninth Mo+2.33+ site, Mo+2.33+ is bonded to five Se2- atoms to form MoSe5 square pyramids that share corners with three MoSe5 square pyramids, an edgeedge with one NaSe6 octahedra, and edges with five MoSe5 square pyramids. There are a spread of Mo–Se bond distances ranging from 2.59–2.79 Å. There are eleven inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 1-coordinate geometry to one Na1+ and four Mo+2.33+ atoms. In the second Se2- site, Se2- is bonded in a 4-coordinate geometry to four Mo+2.33+ atoms. In the third Se2- site, Se2- is bonded in a 5-coordinate geometry to one Na1+ and four Mo+2.33+ atoms. In the fourth Se2- site, Se2- is bonded in a 5-coordinate geometry to one Na1+ and four Mo+2.33+ atoms. In the fifth Se2- site, Se2- is bonded in a 5-coordinate geometry to one Na1+ and four Mo+2.33+ atoms. In the sixth Se2- site, Se2- is bonded in a 5-coordinate geometry to one Na1+ and four Mo+2.33+ atoms. In the seventh Se2- site, Se2- is bonded in a 4-coordinate geometry to one Na1+ and three Mo+2.33+ atoms. In the eighth Se2- site, Se2- is bonded in a 5-coordinate geometry to one Na1+ and four Mo+2.33+ atoms. In the ninth Se2- site, Se2- is bonded in a 5-coordinate geometry to one Na1+ and four Mo+2.33+ atoms. In the tenth Se2- site, Se2- is bonded in a 6-coordinate geometry to two Na1+ and four Mo+2.33+ atoms. In the eleventh Se2- site, Se2- is bonded in a 1-coordinate geometry to one Na1+ and three Mo+2.33+ atoms.