Materials Data on K4CaU(Si2O7)2 by Materials Project

Dataset · Sat May 02 04:00:00 EDT 2020

DOI:https://doi.org/10.17188/1654374· OSTI ID:1654374

K4CaUSi4O14 crystallizes in the tetragonal P-4n2 space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 9-coordinate geometry to seven O2- atoms. There are a spread of K–O bond distances ranging from 2.97–3.21 Å. In the second K1+ site, K1+ is bonded in a 2-coordinate geometry to ten O2- atoms. There are a spread of K–O bond distances ranging from 2.75–3.39 Å. Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with two equivalent UO6 octahedra and corners with four equivalent SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (2.33 Å) and two longer (2.38 Å) Ca–O bond lengths. U6+ is bonded to six O2- atoms to form UO6 octahedra that share corners with two equivalent CaO6 octahedra and corners with four equivalent SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (1.88 Å) and four longer (2.23 Å) U–O bond lengths. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one CaO6 octahedra, a cornercorner with one UO6 octahedra, and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 21–28°. There are a spread of Si–O bond distances ranging from 1.59–1.67 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to three K1+, one U6+, and one Si4+ atom. In the second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent K1+ and two equivalent Si4+ atoms. In the third O2- site, O2- is bonded in a linear geometry to three K1+ and two equivalent Si4+ atoms. In the fourth O2- site, O2- is bonded in a distorted linear geometry to two equivalent K1+, one Ca2+, and one U6+ atom. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to two K1+, one Ca2+, and one Si4+ atom.

• Research Organization: LBNL Materials Project; Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
• Contributing Organization: The Materials Project; MIT; UC Berkeley; Duke; U Louvain
• DOE Contract Number: AC02-05CH11231
• OSTI ID: 1654374
• Report Number(s): mp-1195727
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
Ca-K-O-Si-U
K4CaU(Si2O7)2
crystal structure