Materials Data on LiAlSi2H2O7 by Materials Project

Abstract

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 in a 3-coordinate geometry to one H1+ and three O2- atoms. The Li–H bond length is 2.24 Å. There are a spread of Li–O bond distances ranging from 1.83–2.13 Å. In the second Li1+ site, Li1+ is bonded in a distorted rectangular see-saw-like geometry to four O2- atoms. There are a spread of Li–O bond distances ranging from 1.85–2.16 Å. There are two inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to five O2- atoms to form distorted AlO5 trigonal bipyramids that share a cornercorner with one AlHO5 octahedra, corners with two SiHO3 tetrahedra, and corners with two equivalent SiO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 26°. There are a spread of Al–O bond distances ranging from 1.75–2.12 Å. In the second Al3+ site, Al3+ is bonded to one H1+ and five O2- atoms to form distorted AlHO5 octahedra that share corners with two SiO4 tetrahedra, a cornercorner with one AlO5 trigonal bipyramid, an edgeedge with one SiHO3 tetrahedra, and an edgeedge with one SiO5 trigonal bipyramid. The Al–H bond length is 1.62 Å. There are a spread of Al–O bond distances ranging from 1.81–2.10 Å. There are four inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to five O2- atoms to form SiO5 trigonal bipyramids that share corners with two SiHO3 tetrahedra, corners with two equivalent AlO5 trigonal bipyramids, and an edgeedge with one AlHO5 octahedra. There are a spread of Si–O bond distances ranging from 1.63–1.90 Å. In the second Si4+ site, Si4+ is bonded to one H1+ and three O2- atoms to form SiHO3 tetrahedra that share a cornercorner with one SiO4 tetrahedra, a cornercorner with one AlO5 trigonal bipyramid, a cornercorner with one SiO5 trigonal bipyramid, and an edgeedge with one AlHO5 octahedra. The Si–H bond length is 1.46 Å. There are a spread of Si–O bond distances ranging from 1.63–1.68 Å. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one AlHO5 octahedra, a cornercorner with one SiO4 tetrahedra, and a cornercorner with one SiO5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 77°. There are a spread of Si–O bond distances ranging from 1.57–1.73 Å. In the fourth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one AlHO5 octahedra, corners with two SiHO3 tetrahedra, and a cornercorner with one AlO5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 41°. There are a spread of Si–O bond distances ranging from 1.59–1.66 Å. There are four inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one Al3+ atom. In the second 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 third H1+ site, H1+ is bonded in a distorted L-shaped geometry to one Li1+ and one Si4+ atom. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. There are fourteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a T-shaped 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 Si4+, and one H1+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to two Al3+ and one O2- atom. The O–O bond length is 1.49 Å. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to one Al3+ and one Si4+ atom. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to two Li1+, one Al3+, and one Si4+ atom. In the sixth O2- site, O2- is bonded in a distorted T-shaped geometry to one Al3+ and two Si4+ atoms. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+ and one Al3+ atom. In the eighth O2- site, O2- is bonded in a bent 120 degrees geometry to two Si4+ atoms. In the ninth O2- site, O2- is bonded in a 1-coordinate geometry to one Al3+, one Si4+, and one H1+ atom. In the tenth O2- site, O2- is bonded in a distorted single-bond geometry to one Si4+ atom. In the eleventh O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to one Al3+ and two Si4+ atoms. In the twelfth O2- site, O2- is bonded in a trigonal non-coplanar geometry to two Li1+ and one Si4+ atom. In the thirteenth O2- site, O2- is bonded in a distorted single-bond geometry to one Si4+ and one O2- atom. In the fourteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Al3+ and two Si4+ atoms.