DOI: 10.17188/1704102
title: Materials Data on Ca3SiS2O25 by Materials Project

description: Ca3SiO18SO3SO4 crystallizes in the monoclinic P2_1 space group. The structure is one-dimensional and consists of two sulfur trioxide molecules; two sulfuric acid molecules; and one Ca3SiO18 ribbon oriented in the (0, 1, 0) direction. In the Ca3SiO18 ribbon, there are three inequivalent Ca sites. In the first Ca site, Ca is bonded in a 7-coordinate geometry to seven O atoms. There are a spread of Ca–O bond distances ranging from 2.42–2.74 Å. In the second Ca site, Ca is bonded in a 7-coordinate geometry to seven O atoms. There are a spread of Ca–O bond distances ranging from 2.42–2.73 Å. In the third Ca site, Ca is bonded in a 7-coordinate geometry to seven O atoms. There are a spread of Ca–O bond distances ranging from 2.42–2.75 Å. Si is bonded in an octahedral geometry to six O atoms. There is three shorter (1.78 Å) and three longer (1.79 Å) Si–O bond length. There are eighteen inequivalent O sites. In the first O site, O is bonded to two Ca, one Si, and one O atom to form a mixture of distorted edge and corner-sharing OCa2SiO tetrahedra. The O–O bond length is 1.44 Å. In the second O site, O is bonded to two Ca, one Si, and one O atom to form a mixture of distorted edge and corner-sharing OCa2SiO tetrahedra. The O–O bond length is 1.44 Å. In the third O site, O is bonded to two Ca, one Si, and one O atom to form a mixture of distorted edge and corner-sharing OCa2SiO tetrahedra. The O–O bond length is 1.44 Å. In the fourth O site, O is bonded to two Ca, one Si, and one O atom to form a mixture of distorted edge and corner-sharing OCa2SiO tetrahedra. The O–O bond length is 1.44 Å. In the fifth O site, O is bonded to two Ca, one Si, and one O atom to form a mixture of distorted edge and corner-sharing OCa2SiO tetrahedra. The O–O bond length is 1.44 Å. In the sixth O site, O is bonded to two Ca, one Si, and one O atom to form a mixture of distorted edge and corner-sharing OCa2SiO tetrahedra. The O–O bond length is 1.44 Å. In the seventh O site, O is bonded in a distorted water-like geometry to one Ca and one O atom. In the eighth O site, O is bonded in a distorted water-like geometry to one Ca and one O atom. In the ninth O site, O is bonded in a distorted water-like geometry to one Ca and one O atom. In the tenth O site, O is bonded in a single-bond geometry to one O atom. The O–O bond length is 1.23 Å. In the eleventh O site, O is bonded in a single-bond geometry to one O atom. The O–O bond length is 1.23 Å. In the twelfth O site, O is bonded in a single-bond geometry to one O atom. The O–O bond length is 1.23 Å. In the thirteenth O site, O is bonded in a bent 120 degrees geometry to one Ca and one O atom. In the fourteenth O site, O is bonded in a bent 120 degrees geometry to one Ca and one O atom. In the fifteenth O site, O is bonded in a bent 120 degrees geometry to one Ca and one O atom. In the sixteenth O site, O is bonded in a bent 120 degrees geometry to one Ca and one O atom. In the seventeenth O site, O is bonded in a bent 120 degrees geometry to one Ca and one O atom. In the eighteenth O site, O is bonded in a bent 120 degrees geometry to one Ca and one O atom.