DOI: 10.17188/1285274
title: Materials Data on LiAlSi2H2O7 by Materials Project

description: LiAlSi2H2O7 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are two inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to four O2- atoms to form LiO4 trigonal pyramids that share corners with three AlO4 tetrahedra, corners with three SiO4 tetrahedra, and a cornercorner with one SiO5 trigonal bipyramid. There are a spread of Li–O bond distances ranging from 2.04–2.26 Å. In the second Li1+ site, Li1+ is bonded to four O2- atoms to form LiO4 tetrahedra that share corners with three AlO4 tetrahedra and corners with three SiO4 tetrahedra. There are a spread of Li–O bond distances ranging from 1.92–2.04 Å. There are two inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share a cornercorner with one LiO4 tetrahedra, corners with three SiO4 tetrahedra, a cornercorner with one SiO5 trigonal bipyramid, and corners with two equivalent LiO4 trigonal pyramids. There are a spread of Al–O bond distances ranging from 1.76–1.80 Å. In the second Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with two equivalent LiO4 tetrahedra, corners with four SiO4 tetrahedra, and a cornercorner with one LiO4 trigonal pyramid. There are a spread of Al–O bond distances ranging from 1.74–1.85 Å. There are four 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 LiO4 tetrahedra, corners with three AlO4 tetrahedra, a cornercorner with one SiO5 trigonal bipyramid, and corners with two equivalent LiO4 trigonal pyramids. There are a spread of Si–O bond distances ranging from 1.61–1.65 Å. In the second Si4+ site, Si4+ is bonded to five O2- atoms to form SiO5 trigonal bipyramids that share a cornercorner with one AlO4 tetrahedra, corners with three SiO4 tetrahedra, and a cornercorner with one LiO4 trigonal pyramid. There are a spread of Si–O bond distances ranging from 1.67–1.85 Å. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one AlO4 tetrahedra, a cornercorner with one SiO4 tetrahedra, and corners with two equivalent SiO5 trigonal bipyramids. There are a spread of Si–O bond distances ranging from 1.59–1.75 Å. In the fourth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one SiO4 tetrahedra, corners with two equivalent LiO4 tetrahedra, corners with three AlO4 tetrahedra, and a cornercorner with one LiO4 trigonal pyramid. There is two shorter (1.63 Å) and two longer (1.65 Å) Si–O bond length. There are four 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 0.98 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 1.01 Å. In the third 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 fourth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 1.02 Å. There are fourteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a trigonal planar geometry to one Li1+, one Al3+, and one Si4+ atom. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to one Li1+, one Al3+, and one Si4+ atom. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the fifth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Al3+ and one Si4+ atom. In the sixth O2- site, O2- is bonded in a trigonal planar geometry to one Li1+, one Al3+, and one Si4+ atom. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Si4+, and one H1+ atom. In the eighth O2- site, O2- is bonded in a trigonal planar geometry to one Li1+, one Al3+, and one Si4+ atom. In the ninth O2- site, O2- is bonded in a trigonal planar geometry to one Li1+, one Al3+, and one Si4+ atom. In the tenth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to one Al3+, one Si4+, and one H1+ atom. In the eleventh O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the twelfth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the thirteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Li1+, one Al3+, and one Si4+ atom. In the fourteenth O2- site, O2- is bonded in a distorted water-like geometry to one Li1+ and two H1+ atoms.