Materials Data on Mg19Al4Zn15 by Materials Project

Abstract

Mg19Zn15Al4 is Bergman Structure: Mg32(Al,Zn)49 Bergman-like structured and crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. there are eight inequivalent Mg sites. In the first Mg site, Mg is bonded in a 6-coordinate geometry to six Mg, six Zn, and one Al atom. There are a spread of Mg–Mg bond distances ranging from 2.91–3.25 Å. There are a spread of Mg–Zn bond distances ranging from 2.89–3.29 Å. The Mg–Al bond length is 3.05 Å. In the second Mg site, Mg is bonded in a 1-coordinate geometry to two equivalent Mg and five Zn atoms. There are one shorter (3.00 Å) and one longer (3.41 Å) Mg–Mg bond lengths. There are a spread of Mg–Zn bond distances ranging from 2.84–2.99 Å. In the third Mg site, Mg is bonded in a 12-coordinate geometry to four Mg, eight Zn, and four equivalent Al atoms. There are two shorter (3.04 Å) and two longer (3.13 Å) Mg–Mg bond lengths. There are a spread of Mg–Zn bond distances ranging from 2.98–3.14 Å. All Mg–Al bond lengths are 3.19 Å. In the fourth Mg site, Mg is bonded in a 1-coordinate geometry to three Mg, five Zn, and two equivalent Al atoms. The Mg–Mg bond length is 3.06 Å. There are a spread of Mg–Zn bond distances ranging from 2.79–3.15 Å. There are one shorter (2.97 Å) and one longer (3.00 Å) Mg–Al bond lengths. In the fifth Mg site, Mg is bonded in a 12-coordinate geometry to four Mg, seven Zn, and four equivalent Al atoms. The Mg–Mg bond length is 2.96 Å. There are a spread of Mg–Zn bond distances ranging from 3.12–3.22 Å. There are two shorter (3.01 Å) and two longer (3.23 Å) Mg–Al bond lengths. In the sixth Mg site, Mg is bonded in a 1-coordinate geometry to one Mg, five Zn, and two equivalent Al atoms. There are a spread of Mg–Zn bond distances ranging from 2.69–2.97 Å. Both Mg–Al bond lengths are 3.02 Å. In the seventh Mg site, Mg is bonded in a 12-coordinate geometry to four Mg, five Zn, and two equivalent Al atoms. The Mg–Mg bond length is 3.06 Å. There are two shorter (2.92 Å) and three longer (2.99 Å) Mg–Zn bond lengths. Both Mg–Al bond lengths are 3.01 Å. In the eighth Mg site, Mg is bonded in a 12-coordinate geometry to five Mg and eight Zn atoms. There are a spread of Mg–Zn bond distances ranging from 2.86–3.10 Å. There are six inequivalent Zn sites. In the first Zn site, Zn is bonded to seven Mg, four Zn, and one Al atom to form distorted ZnMg7AlZn4 cuboctahedra that share corners with two equivalent ZnMg7AlZn4 cuboctahedra, corners with three equivalent AlMg8AlZn3 cuboctahedra, an edgeedge with one ZnMg7AlZn4 cuboctahedra, faces with four equivalent AlMg8AlZn3 cuboctahedra, and faces with five ZnMg7AlZn4 cuboctahedra. There are a spread of Zn–Zn bond distances ranging from 2.66–2.72 Å. The Zn–Al bond length is 2.62 Å. In the second Zn site, Zn is bonded in a 1-coordinate geometry to seven Mg, one Zn, and two equivalent Al atoms. The Zn–Zn bond length is 2.58 Å. Both Zn–Al bond lengths are 2.69 Å. In the third Zn site, Zn is bonded to eight Mg and four equivalent Zn atoms to form ZnMg8Zn4 cuboctahedra that share faces with four equivalent AlMg8AlZn3 cuboctahedra and faces with six ZnMg7AlZn4 cuboctahedra. In the fourth Zn site, Zn is bonded in a 12-coordinate geometry to eight Mg, three Zn, and one Al atom. There are one shorter (2.71 Å) and one longer (2.79 Å) Zn–Zn bond lengths. The Zn–Al bond length is 2.64 Å. In the fifth Zn site, Zn is bonded to seven Mg and five Zn atoms to form ZnMg7Zn5 cuboctahedra that share edges with four equivalent AlMg8AlZn3 cuboctahedra, faces with four equivalent AlMg8AlZn3 cuboctahedra, and faces with six ZnMg7AlZn4 cuboctahedra. The Zn–Zn bond length is 2.62 Å. In the sixth Zn site, Zn is bonded in a 10-coordinate geometry to eight Mg and two equivalent Zn atoms. Al is bonded to eight Mg, three Zn, and one Al atom to form distorted AlMg8AlZn3 cuboctahedra that share corners with three equivalent ZnMg7AlZn4 cuboctahedra, corners with three equivalent AlMg8AlZn3 cuboctahedra, edges with two equivalent ZnMg7Zn5 cuboctahedra, edges with three equivalent AlMg8AlZn3 cuboctahedra, a faceface with one AlMg8AlZn3 cuboctahedra, and faces with seven ZnMg7AlZn4 cuboctahedra. The Al–Al bond length is 2.77 Å.