DOE OSTI2020
K15Si92 crystallizes in the orthorhombic Pmmm space group. The structure is three-dimensional. there are seven inequivalent K sites. In the first K site, K is bonded in a 8-coordinate geometry to twenty Si atoms. There are a spread of K–Si bond distances ranging from 3.32–3.41 Å. In the second K site, K is bonded in a 8-coordinate geometry to twenty Si atoms. There are a spread of K–Si bond distances ranging from 3.31–3.41 Å. In the third K site, K is bonded in a 12-coordinate geometry to twelve Si atoms. There are a spread of K–Si bond distances ranging from 3.49–3.66 Å. In the fourth K site, K is bonded in a 12-coordinate geometry to twelve Si atoms. There are a spread of K–Si bond distances ranging from 3.49–3.66 Å. In the fifth K site, K is bonded in a 12-coordinate geometry to twelve Si atoms. There are eight shorter (3.49 Å) and four longer (3.66 Å) K–Si bond lengths. In the sixth K site, K is bonded in a 12-coordinate geometry to twelve Si atoms. There are eight shorter (3.49 Å) and four longer (3.66 Å) K–Si bond lengths. In the seventh K site, K is bonded in a 12-coordinate geometry to twelve Si atoms. There are a spread of K–Si bond distances ranging from 3.49–3.66 Å. There are twenty inequivalent Si sites. In the first Si site, Si is bonded in a distorted body-centered cubic geometry to four K and four Si atoms. All Si–Si bond lengths are 2.42 Å. In the second Si site, Si is bonded to four K and four Si atoms to form a mixture of distorted edge and corner-sharing SiK4Si4 tetrahedra. All Si–Si bond lengths are 2.41 Å. In the third Si site, Si is bonded to four K and four Si atoms to form a mixture of distorted edge and corner-sharing SiK4Si4 tetrahedra. There are three shorter (2.41 Å) and one longer (2.42 Å) Si–Si bond lengths. In the fourth Si site, Si is bonded to four K and four Si atoms to form a mixture of distorted edge and corner-sharing SiK4Si4 tetrahedra. All Si–Si bond lengths are 2.41 Å. In the fifth Si site, Si is bonded in a distorted body-centered cubic geometry to four K and four Si atoms. All Si–Si bond lengths are 2.42 Å. In the sixth Si site, Si is bonded in a 7-coordinate geometry to three K and four Si atoms. There are two shorter (2.39 Å) and one longer (2.47 Å) Si–Si bond lengths. In the seventh Si site, Si is bonded in a 7-coordinate geometry to three K and four Si atoms. Both Si–Si bond lengths are 2.39 Å. In the eighth Si site, Si is bonded in a 7-coordinate geometry to three K and four Si atoms. There are two shorter (2.39 Å) and one longer (2.47 Å) Si–Si bond lengths. In the ninth Si site, Si is bonded in a 7-coordinate geometry to three K and four Si atoms. There are two shorter (2.40 Å) and one longer (2.45 Å) Si–Si bond lengths. In the tenth Si site, Si is bonded in a 7-coordinate geometry to three K and four Si atoms. There are two shorter (2.40 Å) and one longer (2.45 Å) Si–Si bond lengths. In the eleventh Si site, Si is bonded in a 6-coordinate geometry to two equivalent K and four Si atoms. There are two shorter (2.38 Å) and one longer (2.45 Å) Si–Si bond lengths. In the twelfth Si site, Si is bonded in a 7-coordinate geometry to three K and four Si atoms. There are two shorter (2.39 Å) and one longer (2.46 Å) Si–Si bond lengths. In the thirteenth Si site, Si is bonded in a 6-coordinate geometry to two equivalent K and four Si atoms. There are two shorter (2.38 Å) and one longer (2.46 Å) Si–Si bond lengths. In the fourteenth Si site, Si is bonded in a 7-coordinate geometry to three K and four Si atoms. There are two shorter (2.39 Å) and one longer (2.46 Å) Si–Si bond lengths. In the fifteenth Si site, Si is bonded in a 7-coordinate geometry to three K and four Si atoms. There are two shorter (2.39 Å) and one longer (2.47 Å) Si–Si bond lengths. In the sixteenth Si site, Si is bonded in a 6-coordinate geometry to two equivalent K and four Si atoms. There are two shorter (2.38 Å) and one longer (2.46 Å) Si–Si bond lengths. In the seventeenth Si site, Si is bonded in a 8-coordinate geometry to one K and four Si atoms. The Si–Si bond length is 2.34 Å. In the eighteenth Si site, Si is bonded in a 8-coordinate geometry to one K and four Si atoms. The Si–Si bond length is 2.33 Å. In the nineteenth Si site, Si is bonded to four Si atoms to form corner-sharing SiSi4 tetrahedra. In the twentieth Si site, Si is bonded in a 8-coordinate geometry to one K and four Si atoms.