DOI: 10.17188/1740814
title: Materials Data on Ca11Si9As16 by Materials Project

description: Ca11Si9As16 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are eleven inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to six As+2.62- atoms to form a mixture of corner and edge-sharing CaAs6 octahedra. The corner-sharing octahedra tilt angles range from 5–8°. There are a spread of Ca–As bond distances ranging from 2.98–3.06 Å. In the second Ca2+ site, Ca2+ is bonded to six As+2.62- atoms to form a mixture of corner and edge-sharing CaAs6 octahedra. The corner-sharing octahedra tilt angles range from 2–8°. There are a spread of Ca–As bond distances ranging from 2.97–3.10 Å. In the third Ca2+ site, Ca2+ is bonded to six As+2.62- atoms to form a mixture of corner and edge-sharing CaAs6 octahedra. The corner-sharing octahedra tilt angles range from 2–8°. There are a spread of Ca–As bond distances ranging from 2.98–3.09 Å. In the fourth Ca2+ site, Ca2+ is bonded to six As+2.62- atoms to form a mixture of corner and edge-sharing CaAs6 octahedra. The corner-sharing octahedra tilt angles range from 1–5°. There are a spread of Ca–As bond distances ranging from 2.96–3.16 Å. In the fifth Ca2+ site, Ca2+ is bonded to six As+2.62- atoms to form a mixture of corner and edge-sharing CaAs6 octahedra. The corner-sharing octahedra tilt angles range from 4–8°. There are a spread of Ca–As bond distances ranging from 2.98–3.12 Å. In the sixth Ca2+ site, Ca2+ is bonded to six As+2.62- atoms to form a mixture of corner and edge-sharing CaAs6 octahedra. The corner-sharing octahedra tilt angles range from 2–6°. There are a spread of Ca–As bond distances ranging from 2.97–3.16 Å. In the seventh Ca2+ site, Ca2+ is bonded to six As+2.62- atoms to form a mixture of corner and edge-sharing CaAs6 octahedra. The corner-sharing octahedra tilt angles range from 2–6°. There are a spread of Ca–As bond distances ranging from 2.97–3.17 Å. In the eighth Ca2+ site, Ca2+ is bonded to six As+2.62- atoms to form a mixture of corner and edge-sharing CaAs6 octahedra. The corner-sharing octahedra tilt angles range from 1–6°. There are a spread of Ca–As bond distances ranging from 2.99–3.17 Å. In the ninth Ca2+ site, Ca2+ is bonded to six As+2.62- atoms to form a mixture of corner and edge-sharing CaAs6 octahedra. The corner-sharing octahedra tilt angles range from 3–8°. There are a spread of Ca–As bond distances ranging from 2.94–3.12 Å. In the tenth Ca2+ site, Ca2+ is bonded to six As+2.62- atoms to form a mixture of corner and edge-sharing CaAs6 octahedra. The corner-sharing octahedra tilt angles range from 4–8°. There are a spread of Ca–As bond distances ranging from 2.96–3.11 Å. In the eleventh Ca2+ site, Ca2+ is bonded to six As+2.62- atoms to form a mixture of corner and edge-sharing CaAs6 octahedra. The corner-sharing octahedra tilt angles range from 3–6°. There are a spread of Ca–As bond distances ranging from 2.96–3.13 Å. There are nine inequivalent Si+2.22+ sites. In the first Si+2.22+ site, Si+2.22+ is bonded in a trigonal non-coplanar geometry to three As+2.62- atoms. There are a spread of Si–As bond distances ranging from 2.35–2.42 Å. In the second Si+2.22+ site, Si+2.22+ is bonded in a trigonal non-coplanar geometry to three As+2.62- atoms. There are a spread of Si–As bond distances ranging from 2.39–2.47 Å. In the third Si+2.22+ site, Si+2.22+ is bonded in a trigonal non-coplanar geometry to three As+2.62- atoms. There are a spread of Si–As bond distances ranging from 2.36–2.43 Å. In the fourth Si+2.22+ site, Si+2.22+ is bonded in a trigonal non-coplanar geometry to three As+2.62- atoms. There are a spread of Si–As bond distances ranging from 2.35–2.42 Å. In the fifth Si+2.22+ site, Si+2.22+ is bonded in a trigonal non-coplanar geometry to three As+2.62- atoms. There are one shorter (2.39 Å) and two longer (2.40 Å) Si–As bond lengths. In the sixth Si+2.22+ site, Si+2.22+ is bonded in a trigonal non-coplanar geometry to three As+2.62- atoms. There are a spread of Si–As bond distances ranging from 2.39–2.41 Å. In the seventh Si+2.22+ site, Si+2.22+ is bonded in a trigonal non-coplanar geometry to three As+2.62- atoms. There are a spread of Si–As bond distances ranging from 2.39–2.41 Å. In the eighth Si+2.22+ site, Si+2.22+ is bonded in a trigonal non-coplanar geometry to three As+2.62- atoms. There are a spread of Si–As bond distances ranging from 2.39–2.44 Å. In the ninth Si+2.22+ site, Si+2.22+ is bonded in a 2-coordinate geometry to five As+2.62- atoms. There are a spread of Si–As bond distances ranging from 2.70–3.04 Å. There are sixteen inequivalent As+2.62- sites. In the first As+2.62- site, As+2.62- is bonded in a 6-coordinate geometry to three Ca2+ and three Si+2.22+ atoms. In the second As+2.62- site, As+2.62- is bonded to four Ca2+ and two Si+2.22+ atoms to form AsCa4Si2 octahedra that share corners with eight AsCa4Si2 octahedra and edges with eight AsCa5Si octahedra. The corner-sharing octahedra tilt angles range from 5–93°. In the third As+2.62- site, As+2.62- is bonded to four Ca2+ and two Si+2.22+ atoms to form a mixture of corner and edge-sharing AsCa4Si2 octahedra. The corner-sharing octahedra tilt angles range from 5–93°. In the fourth As+2.62- site, As+2.62- is bonded to three Ca2+ and three Si+2.22+ atoms to form distorted AsCa3Si3 octahedra that share corners with four AsCa5Si octahedra, edges with five AsCa4Si2 octahedra, and edges with two equivalent AsCa3Si2 square pyramids. The corner-sharing octahedra tilt angles range from 3–83°. In the fifth As+2.62- site, As+2.62- is bonded to four Ca2+ and two Si+2.22+ atoms to form AsCa4Si2 octahedra that share corners with four AsCa4Si2 octahedra, corners with two equivalent AsCa3Si2 square pyramids, and edges with nine AsCa4Si2 octahedra. The corner-sharing octahedra tilt angles range from 3–7°. In the sixth As+2.62- site, As+2.62- is bonded to five Ca2+ and one Si+2.22+ atom to form a mixture of corner and edge-sharing AsCa5Si octahedra. The corner-sharing octahedra tilt angles range from 4–88°. In the seventh As+2.62- site, As+2.62- is bonded to five Ca2+ and one Si+2.22+ atom to form AsCa5Si octahedra that share corners with five AsCa5Si octahedra, corners with two equivalent AsCa3Si2 square pyramids, and edges with ten AsCa4Si2 octahedra. The corner-sharing octahedra tilt angles range from 3–87°. In the eighth As+2.62- site, As+2.62- is bonded to five Ca2+ and one Si+2.22+ atom to form AsCa5Si octahedra that share corners with five AsCa5Si octahedra, a cornercorner with one AsCa3Si2 square pyramid, and edges with seven AsCa5Si octahedra. The corner-sharing octahedra tilt angles range from 3–83°. In the ninth As+2.62- site, As+2.62- is bonded to three Ca2+ and two Si+2.22+ atoms to form distorted AsCa3Si2 square pyramids that share corners with eight AsCa4Si2 octahedra and edges with three AsCa5Si octahedra. The corner-sharing octahedra tilt angles range from 4–96°. In the tenth As+2.62- site, As+2.62- is bonded to four Ca2+ and two Si+2.22+ atoms to form a mixture of corner and edge-sharing AsCa4Si2 octahedra. The corner-sharing octahedra tilt angles range from 5–92°. In the eleventh As+2.62- site, As+2.62- is bonded to four Ca2+ and two Si+2.22+ atoms to form AsCa4Si2 octahedra that share corners with eight AsCa5Si octahedra and edges with eight AsCa4Si2 octahedra. The corner-sharing octahedra tilt angles range from 3–92°. In the twelfth As+2.62- site, As+2.62- is bonded in a 5-coordinate geometry to three Ca2+ and three Si+2.22+ atoms. In the thirteenth As+2.62- site, As+2.62- is bonded to four Ca2+ and two Si+2.22+ atoms to form AsCa4Si2 octahedra that share corners with four AsCa4Si2 octahedra, corners with two equivalent AsCa3Si2 square pyramids, and edges with nine AsCa5Si octahedra. The corner-sharing octahedra tilt angles range from 5–7°. In the fourteenth As+2.62- site, As+2.62- is bonded to five Ca2+ and one Si+2.22+ atom to form AsCa5Si octahedra that share corners with five AsCa4Si2 octahedra and edges with nine AsCa5Si octahedra. The corner-sharing octahedra tilt angles range from 4–92°. In the fifteenth As+2.62- site, As+2.62- is bonded to five Ca2+ and one Si+2.22+ atom to form AsCa5Si octahedra that share corners with seven AsCa4Si2 octahedra, edges with nine AsCa4Si2 octahedra, and an edgeedge with one AsCa3Si2 square pyramid. The corner-sharing octahedra tilt angles range from 3–92°. In the sixteenth As+2.62- site, As+2.62- is bonded to five Ca2+ and one Si+2.22+ atom to form AsCa5Si octahedra that share corners with five AsCa4Si2 octahedra, a cornercorner with one AsCa3Si2 square pyramid, and edges with seven AsCa5Si octahedra. The corner-sharing octahedra tilt angles range from 3–6°.