Materials Data on Sr6Mg7H26 by Materials Project

Abstract

Sr6Mg7H26 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are three inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded in a 10-coordinate geometry to ten H1- atoms. There are a spread of Sr–H bond distances ranging from 2.42–2.90 Å. In the second Sr2+ site, Sr2+ is bonded in a 11-coordinate geometry to eleven H1- atoms. There are a spread of Sr–H bond distances ranging from 2.53–2.85 Å. In the third Sr2+ site, Sr2+ is bonded in a 10-coordinate geometry to ten H1- atoms. There are a spread of Sr–H bond distances ranging from 2.43–2.87 Å. There are four inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to six H1- atoms to form distorted corner-sharing MgH6 octahedra. The corner-sharing octahedra tilt angles range from 24–49°. There are a spread of Mg–H bond distances ranging from 1.91–2.16 Å. In the second Mg2+ site, Mg2+ is bonded to six H1- atoms to form corner-sharing MgH6 octahedra. The corner-sharing octahedra tilt angles range from 20–58°. There are a spread of Mg–H bond distances ranging from 1.88–2.04 Å. In the third Mg2+ site, Mg2+ is bonded to six H1- atoms to form a mixture of edge and corner-sharing MgH6 octahedra. The corner-sharing octahedra tilt angles range from 49–58°. There is four shorter (1.92 Å) and two longer (1.95 Å) Mg–H bond length. In the fourth Mg2+ site, Mg2+ is bonded to six H1- atoms to form corner-sharing MgH6 octahedra. The corner-sharing octahedra tilt angles range from 20–24°. There is two shorter (1.92 Å) and four longer (1.95 Å) Mg–H bond length. There are nine inequivalent H1- sites. In the first H1- site, H1- is bonded in a 4-coordinate geometry to two Sr2+ and two Mg2+ atoms. In the second H1- site, H1- is bonded to two Sr2+ and two Mg2+ atoms to form a mixture of distorted edge and corner-sharing HSr2Mg2 tetrahedra. In the third H1- site, H1- is bonded in a 2-coordinate geometry to three Sr2+ and one Mg2+ atom. In the fourth H1- site, H1- is bonded in a distorted single-bond geometry to four Sr2+ and one Mg2+ atom. In the fifth H1- site, H1- is bonded in a distorted L-shaped geometry to one Sr2+ and two equivalent Mg2+ atoms. In the sixth H1- site, H1- is bonded in a distorted trigonal planar geometry to three Mg2+ atoms. In the seventh H1- site, H1- is bonded in a 1-coordinate geometry to three Sr2+ and two Mg2+ atoms. In the eighth H1- site, H1- is bonded to three Sr2+ and one Mg2+ atom to form distorted HSr3Mg tetrahedra that share corners with eight HSr2Mg2 tetrahedra and edges with four HSr3Mg tetrahedra. In the ninth H1- site, H1- is bonded to three Sr2+ and one Mg2+ atom to form distorted HSr3Mg tetrahedra that share corners with eight HSr2Mg2 tetrahedra and edges with four HSr3Mg tetrahedra.