Title: Materials Data on CaAl4Si2(HO6)2 by Materials Project

Abstract

CaAl4Si2O10(OH)2 crystallizes in the monoclinic Cc space group. The structure is three-dimensional. Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with six AlO4 tetrahedra and corners with six SiO4 tetrahedra. There are a spread of Ca–O bond distances ranging from 2.43–2.52 Å. There are four inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with two AlO6 octahedra, corners with three equivalent CaO6 octahedra, and corners with three equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 54–64°. There are a spread of Al–O bond distances ranging from 1.74–1.79 Å. In the second Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with two AlO4 tetrahedra, corners with two SiO4 tetrahedra, and edges with three equivalent AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.89–1.97 Å. In the third Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with two AlO4 tetrahedra, corners with two SiO4 tetrahedra, and edges with three equivalent AlO6 octahedra. There are a spread of Al–O bond distancesmore » ranging from 1.87–2.01 Å. In the fourth Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with two AlO6 octahedra, corners with three equivalent CaO6 octahedra, and corners with three equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 53–64°. There are a spread of Al–O bond distances ranging from 1.74–1.79 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 corners with two AlO6 octahedra, corners with three equivalent CaO6 octahedra, and corners with three equivalent AlO4 tetrahedra. The corner-sharing octahedra tilt angles range from 51–61°. There are a spread of Si–O bond distances ranging from 1.64–1.66 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two AlO6 octahedra, corners with three equivalent CaO6 octahedra, and corners with three equivalent AlO4 tetrahedra. The corner-sharing octahedra tilt angles range from 52–61°. There is one shorter (1.64 Å) and three longer (1.65 Å) Si–O bond length. There are two inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.97 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.97 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two Al3+ and one H1+ atom. In the second O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two Al3+ and one H1+ atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+, one Al3+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+, one Al3+, and one Si4+ atom. In the fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+, one Al3+, and one Si4+ atom. In the sixth O2- site, O2- is bonded in a trigonal planar geometry to three Al3+ atoms. In the seventh O2- site, O2- is bonded in a distorted trigonal planar geometry to two Al3+ and one Si4+ atom. In the eighth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Al3+ and one Si4+ atom. In the ninth O2- site, O2- is bonded in a trigonal planar geometry to three Al3+ atoms. In the tenth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+, one Al3+, and one Si4+ atom. In the eleventh O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+, one Al3+, and one Si4+ atom. In the twelfth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+, one Al3+, and one Si4+ atom.« less

Authors:

The Materials Project

Publication Date:

Sat Jul 18 00:00:00 EDT 2020

Other Number(s):

mp-24469

DOE Contract Number:  

AC02-05CH11231; EDCBEE

Research Org.:

Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). LBNL Materials Project

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES)

Collaborations:

MIT; UC Berkeley; Duke; U Louvain

Subject:

36 MATERIALS SCIENCE

Keywords:

crystal structure; CaAl4Si2(HO6)2; Al-Ca-H-O-Si

OSTI Identifier:

1200111

DOI:

https://doi.org/10.17188/1200111