DOI: 10.17188/1712332
title: Materials Data on Na2Cu2Si5(H3O8)2 by Materials Project

description: Na2Cu2Si5(H3O8)2 crystallizes in the monoclinic Pc space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to six O2- atoms to form NaO6 octahedra that share corners with five SiO4 tetrahedra and an edgeedge with one CuO5 square pyramid. There are a spread of Na–O bond distances ranging from 2.28–2.62 Å. In the second Na1+ site, Na1+ is bonded to five O2- atoms to form NaO5 square pyramids that share a cornercorner with one CuO5 square pyramid, corners with five SiO4 tetrahedra, and an edgeedge with one CuO5 square pyramid. There are a spread of Na–O bond distances ranging from 2.24–2.49 Å. There are two inequivalent Cu2+ sites. In the first Cu2+ site, Cu2+ is bonded in a 4-coordinate geometry to five O2- atoms. There are a spread of Cu–O bond distances ranging from 1.96–2.68 Å. In the second Cu2+ site, Cu2+ is bonded to five O2- atoms to form distorted CuO5 square pyramids that share a cornercorner with one NaO5 square pyramid, corners with five SiO4 tetrahedra, an edgeedge with one NaO6 octahedra, and an edgeedge with one NaO5 square pyramid. There are a spread of Cu–O bond distances ranging from 1.96–2.59 Å. There are five 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 NaO6 octahedra, a cornercorner with one CuO5 square pyramid, and corners with three SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 54°. There are a spread of Si–O bond distances ranging from 1.60–1.67 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one NaO5 square pyramid, a cornercorner with one CuO5 square pyramid, and corners with three SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.60–1.67 Å. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two equivalent NaO6 octahedra, a cornercorner with one CuO5 square pyramid, corners with two equivalent NaO5 square pyramids, and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 47–74°. There are a spread of Si–O bond distances ranging from 1.61–1.69 Å. In the fourth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one NaO6 octahedra, a cornercorner with one NaO5 square pyramid, a cornercorner with one CuO5 square pyramid, and corners with three SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 68°. There are a spread of Si–O bond distances ranging from 1.63–1.65 Å. In the fifth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one NaO6 octahedra, a cornercorner with one NaO5 square pyramid, a cornercorner with one CuO5 square pyramid, and corners with three SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 51°. There are a spread of Si–O bond distances ranging from 1.63–1.65 Å. There are six 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 0.98 Å. In the third H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the fourth 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 fifth 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 sixth 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 sixteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the second O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Cu2+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Cu2+, and one Si4+ atom. In the fifth O2- site, O2- is bonded in a distorted water-like geometry to one Na1+ and two H1+ atoms. In the sixth O2- site, O2- is bonded in a distorted water-like geometry to one Na1+ and two H1+ atoms. In the seventh O2- site, O2- is bonded in a distorted trigonal planar geometry to one Na1+ and two Si4+ atoms. In the eighth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Na1+ and two Si4+ atoms. In the ninth O2- site, O2- is bonded in a bent 120 degrees geometry to two Si4+ atoms. In the tenth O2- site, O2- is bonded in a bent 120 degrees geometry to two Si4+ atoms. In the eleventh O2- site, O2- is bonded in a linear geometry to two Si4+ atoms. In the twelfth O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, two Cu2+, and one Si4+ atom. In the thirteenth O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, two Cu2+, and one Si4+ atom. In the fourteenth O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, two Cu2+, and one Si4+ atom. In the fifteenth O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, two Cu2+, and one Si4+ atom. In the sixteenth O2- site, O2- is bonded in a water-like geometry to one Na1+ and two H1+ atoms.