Materials Data on CaAl2Si4(H2O7)2 by Materials Project

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

DOI:https://doi.org/10.17188/1286241· OSTI ID:1286241

CaAl2Si4(HO7)2H2 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional and consists of four hydrogen molecules and one CaAl2Si4(HO7)2 framework. In the CaAl2Si4(HO7)2 framework, Ca2+ is bonded to six O2- atoms to form distorted CaO6 pentagonal pyramids that share corners with four SiO4 tetrahedra and edges with two equivalent AlO4 tetrahedra. There are two shorter (2.38 Å) and four longer (2.40 Å) Ca–O bond lengths. Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with four SiO4 tetrahedra and an edgeedge with one CaO6 pentagonal pyramid. There are a spread of Al–O bond distances ranging from 1.72–1.79 Å. There are two inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one CaO6 pentagonal pyramid, corners with two equivalent AlO4 tetrahedra, and corners with two SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.60–1.65 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one CaO6 pentagonal pyramid, corners with two equivalent AlO4 tetrahedra, and corners with two SiO4 tetrahedra. There is one shorter (1.61 Å) and three longer (1.64 Å) Si–O bond length. H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to one Al3+ and one Si4+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to one Ca2+ and one H1+ atom. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent Si4+ atoms. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Al3+, and one Si4+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Al3+, and one Si4+ atom. In the sixth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the seventh O2- site, O2- is bonded in a bent 150 degrees geometry to one Al3+ and one Si4+ atom. In the eighth O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent Si4+ atoms.

• 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: 1286241
• Report Number(s): mp-706640
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
Al-Ca-H-O-Si
CaAl2Si4(H2O7)2
crystal structure