Materials Data on Sr13Al6Si8O by Materials Project

Abstract

Sr13Al6Si8O crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are seven inequivalent Sr sites. In the first Sr site, Sr is bonded in a 7-coordinate geometry to two equivalent Al and five Si atoms. Both Sr–Al bond lengths are 3.36 Å. There are a spread of Sr–Si bond distances ranging from 3.29–3.39 Å. In the second Sr site, Sr is bonded in a single-bond geometry to four Al, four Si, and one O atom. There are two shorter (3.42 Å) and two longer (3.44 Å) Sr–Al bond lengths. There are two shorter (3.44 Å) and two longer (3.47 Å) Sr–Si bond lengths. The Sr–O bond length is 2.50 Å. In the third Sr site, Sr is bonded to eight Al and four Si atoms to form a mixture of edge and face-sharing SrAl8Si4 cuboctahedra. There are a spread of Sr–Al bond distances ranging from 3.44–3.48 Å. There are two shorter (3.57 Å) and two longer (3.61 Å) Sr–Si bond lengths. In the fourth Sr site, Sr is bonded in a 7-coordinate geometry to two equivalent Al and five Si atoms. Both Sr–Al bond lengths are 3.31 Å. There are a spread of Sr–Si bond distances ranging from 3.25–3.41 Å. In the fifth Sr site, Sr is bonded in a 7-coordinate geometry to two equivalent Al and five Si atoms. Both Sr–Al bond lengths are 3.29 Å. There are a spread of Sr–Si bond distances ranging from 3.29–3.40 Å. In the sixth Sr site, Sr is bonded in a distorted single-bond geometry to five Si and one O atom. There are four shorter (3.41 Å) and one longer (3.75 Å) Sr–Si bond lengths. The Sr–O bond length is 2.89 Å. In the seventh Sr site, Sr is bonded in a linear geometry to four Si and two equivalent O atoms. There are two shorter (3.41 Å) and two longer (3.42 Å) Sr–Si bond lengths. Both Sr–O bond lengths are 2.42 Å. There are three inequivalent Al sites. In the first Al site, Al is bonded in a 2-coordinate geometry to six Sr, one Al, and two Si atoms. The Al–Al bond length is 2.59 Å. There are one shorter (2.49 Å) and one longer (2.51 Å) Al–Si bond lengths. In the second Al site, Al is bonded in a 2-coordinate geometry to six Sr, one Al, and two Si atoms. The Al–Al bond length is 2.59 Å. There are one shorter (2.50 Å) and one longer (2.53 Å) Al–Si bond lengths. In the third Al site, Al is bonded in a distorted bent 120 degrees geometry to six Sr, one Al, and two Si atoms. There are one shorter (2.48 Å) and one longer (2.51 Å) Al–Si bond lengths. There are four inequivalent Si sites. In the first Si site, Si is bonded in a 2-coordinate geometry to seven Sr and two Al atoms. In the second Si site, Si is bonded in a 2-coordinate geometry to seven Sr and two Al atoms. In the third Si site, Si is bonded in a 9-coordinate geometry to eight Sr and one Al atom. In the fourth Si site, Si is bonded in a 9-coordinate geometry to eight Sr and one Al atom. O is bonded to six Sr atoms to form corner-sharing OSr6 octahedra. The corner-sharing octahedral tilt angles are 0°.