Materials Data on Ba2Mo15Se19 by Materials Project
Ba2Mo15Se19 crystallizes in the trigonal R-3c space group. The structure is three-dimensional. Ba2+ is bonded in a 5-coordinate geometry to eleven Se2- atoms. There are a spread of Ba–Se bond distances ranging from 3.30–3.93 Å. There are three inequivalent Mo+2.27+ sites. In the first Mo+2.27+ site, Mo+2.27+ is bonded in a see-saw-like geometry to four Se2- atoms. There are two shorter (2.58 Å) and two longer (2.62 Å) Mo–Se bond lengths. In the second Mo+2.27+ site, Mo+2.27+ is bonded to five Se2- atoms to form a mixture of corner and edge-sharing MoSe5 square pyramids. There are a spread of Mo–Se bond distances ranging from 2.57–2.66 Å. In the third Mo+2.27+ site, Mo+2.27+ is bonded to five Se2- atoms to form a mixture of corner and edge-sharing MoSe5 square pyramids. There are a spread of Mo–Se bond distances ranging from 2.56–2.73 Å. There are five inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 4-coordinate geometry to one Ba2+ and three equivalent Mo+2.27+ atoms. In the second Se2- site, Se2- is bonded in a 4-coordinate geometry to one Ba2+ and four Mo+2.27+ atoms. In the third Se2- site, Se2- is bonded in a 7-coordinate geometry to one Ba2+ and three equivalent Mo+2.27+ atoms. In the fourth Se2- site, Se2- is bonded in a 5-coordinate geometry to one Ba2+ and four Mo+2.27+ atoms. In the fifth Se2- site, Se2- is bonded in a 4-coordinate geometry to two equivalent Ba2+ and four Mo+2.27+ atoms.