Materials Data on Mn3Al9Si by Materials Project
Mn3Al9Si crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Mn is bonded in a 12-coordinate geometry to two equivalent Mn, eight Al, and two equivalent Si atoms. Both Mn–Mn bond lengths are 2.68 Å. There are a spread of Mn–Al bond distances ranging from 2.42–2.67 Å. Both Mn–Si bond lengths are 2.46 Å. There are four inequivalent Al sites. In the first Al site, Al is bonded in a 1-coordinate geometry to three equivalent Mn, nine Al, and one Si atom. There are a spread of Al–Al bond distances ranging from 2.77–2.99 Å. The Al–Si bond length is 2.65 Å. In the second Al site, Al is bonded in a 1-coordinate geometry to three equivalent Mn, nine Al, and one Si atom. There are a spread of Al–Al bond distances ranging from 2.77–2.99 Å. The Al–Si bond length is 2.65 Å. In the third Al site, Al is bonded in a 1-coordinate geometry to three equivalent Mn, nine Al, and one Si atom. There are a spread of Al–Al bond distances ranging from 2.77–2.93 Å. The Al–Si bond length is 2.65 Å. In the fourth Al site, Al is bonded in a distorted linear geometry to two equivalent Mn and eight Al atoms. Si is bonded to six equivalent Mn and six Al atoms to form face-sharing SiMn6Al6 cuboctahedra.