DOI: 10.17188/1282409
title: Materials Data on Mg5(AlSe4)2 by Materials Project

description: Mg5(AlSe4)2 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are twenty inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to five Se2- atoms to form distorted MgSe5 trigonal bipyramids that share a cornercorner with one AlSe4 tetrahedra, a cornercorner with one AlSe5 trigonal bipyramid, and an edgeedge with one AlSe4 tetrahedra. There are a spread of Mg–Se bond distances ranging from 2.57–3.06 Å. In the second Mg2+ site, Mg2+ is bonded in a 5-coordinate geometry to five Se2- atoms. There are a spread of Mg–Se bond distances ranging from 2.58–3.23 Å. In the third Mg2+ site, Mg2+ is bonded in a 4-coordinate geometry to five Se2- atoms. There are a spread of Mg–Se bond distances ranging from 2.56–3.37 Å. In the fourth Mg2+ site, Mg2+ is bonded to five Se2- atoms to form distorted MgSe5 square pyramids that share a cornercorner with one AlSe4 tetrahedra, corners with two equivalent MgSe5 trigonal bipyramids, an edgeedge with one MgSe4 tetrahedra, and edges with two AlSe5 trigonal bipyramids. There are a spread of Mg–Se bond distances ranging from 2.56–3.09 Å. In the fifth Mg2+ site, Mg2+ is bonded in a rectangular see-saw-like geometry to four Se2- atoms. There are a spread of Mg–Se bond distances ranging from 2.60–2.87 Å. In the sixth Mg2+ site, Mg2+ is bonded in a 4-coordinate geometry to four Se2- atoms. There are a spread of Mg–Se bond distances ranging from 2.63–2.73 Å. In the seventh Mg2+ site, Mg2+ is bonded in a distorted square co-planar geometry to four Se2- atoms. There are a spread of Mg–Se bond distances ranging from 2.56–2.83 Å. In the eighth Mg2+ site, Mg2+ is bonded to four Se2- atoms to form MgSe4 tetrahedra that share corners with two AlSe4 tetrahedra, a cornercorner with one MgSe5 trigonal bipyramid, corners with two AlSe5 trigonal bipyramids, a cornercorner with one MgSe4 trigonal pyramid, and an edgeedge with one MgSe5 square pyramid. There are a spread of Mg–Se bond distances ranging from 2.54–2.65 Å. In the ninth Mg2+ site, Mg2+ is bonded in a rectangular see-saw-like geometry to four Se2- atoms. There are a spread of Mg–Se bond distances ranging from 2.53–2.74 Å. In the tenth Mg2+ site, Mg2+ is bonded to five Se2- atoms to form distorted MgSe5 trigonal bipyramids that share corners with four MgSe5 square pyramids, a cornercorner with one MgSe4 tetrahedra, a cornercorner with one AlSe4 tetrahedra, an edgeedge with one MgSe5 trigonal bipyramid, an edgeedge with one AlSe5 trigonal bipyramid, and a faceface with one AlSe5 trigonal bipyramid. There are a spread of Mg–Se bond distances ranging from 2.56–2.87 Å. In the eleventh Mg2+ site, Mg2+ is bonded in a 4-coordinate geometry to four Se2- atoms. There are a spread of Mg–Se bond distances ranging from 2.61–2.69 Å. In the twelfth Mg2+ site, Mg2+ is bonded to five Se2- atoms to form distorted MgSe5 trigonal bipyramids that share corners with two AlSe5 trigonal bipyramids, a cornercorner with one MgSe4 trigonal pyramid, an edgeedge with one MgSe5 square pyramid, and an edgeedge with one MgSe5 trigonal bipyramid. There are a spread of Mg–Se bond distances ranging from 2.57–2.91 Å. In the thirteenth Mg2+ site, Mg2+ is bonded to four Se2- atoms to form distorted MgSe4 trigonal pyramids that share a cornercorner with one MgSe4 tetrahedra, corners with two AlSe4 tetrahedra, a cornercorner with one MgSe4 trigonal pyramid, and an edgeedge with one AlSe5 trigonal bipyramid. There are a spread of Mg–Se bond distances ranging from 2.54–2.64 Å. In the fourteenth Mg2+ site, Mg2+ is bonded to five Se2- atoms to form distorted MgSe5 square pyramids that share a cornercorner with one AlSe4 tetrahedra, a cornercorner with one AlSe5 trigonal bipyramid, corners with two equivalent MgSe5 trigonal bipyramids, an edgeedge with one MgSe5 trigonal bipyramid, an edgeedge with one AlSe5 trigonal bipyramid, and an edgeedge with one MgSe4 trigonal pyramid. There are a spread of Mg–Se bond distances ranging from 2.61–3.26 Å. In the fifteenth Mg2+ site, Mg2+ is bonded in a see-saw-like geometry to four Se2- atoms. There are a spread of Mg–Se bond distances ranging from 2.61–2.79 Å. In the sixteenth Mg2+ site, Mg2+ is bonded in a distorted see-saw-like geometry to four Se2- atoms. There are a spread of Mg–Se bond distances ranging from 2.54–2.72 Å. In the seventeenth Mg2+ site, Mg2+ is bonded in a 4-coordinate geometry to four Se2- atoms. There are a spread of Mg–Se bond distances ranging from 2.61–3.00 Å. In the eighteenth Mg2+ site, Mg2+ is bonded to four Se2- atoms to form distorted MgSe4 trigonal pyramids that share a cornercorner with one AlSe4 tetrahedra, a cornercorner with one MgSe5 trigonal bipyramid, a cornercorner with one AlSe5 trigonal bipyramid, a cornercorner with one MgSe4 trigonal pyramid, and an edgeedge with one MgSe5 square pyramid. There are a spread of Mg–Se bond distances ranging from 2.55–2.70 Å. In the nineteenth Mg2+ site, Mg2+ is bonded in a distorted T-shaped geometry to three Se2- atoms. There are a spread of Mg–Se bond distances ranging from 2.55–3.09 Å. In the twentieth Mg2+ site, Mg2+ is bonded in a 3-coordinate geometry to three Se2- atoms. There are a spread of Mg–Se bond distances ranging from 2.50–2.79 Å. There are eight inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to five Se2- atoms to form AlSe5 trigonal bipyramids that share a cornercorner with one AlSe4 tetrahedra, a cornercorner with one MgSe5 trigonal bipyramid, edges with two MgSe5 square pyramids, and a faceface with one MgSe5 trigonal bipyramid. There are a spread of Al–Se bond distances ranging from 2.52–2.67 Å. In the second Al3+ site, Al3+ is bonded in a distorted see-saw-like geometry to four Se2- atoms. There are a spread of Al–Se bond distances ranging from 2.39–2.51 Å. In the third Al3+ site, Al3+ is bonded in a distorted see-saw-like geometry to four Se2- atoms. There are a spread of Al–Se bond distances ranging from 2.63–2.93 Å. In the fourth Al3+ site, Al3+ is bonded to four Se2- atoms to form AlSe4 tetrahedra that share a cornercorner with one MgSe5 square pyramid, a cornercorner with one MgSe4 tetrahedra, a cornercorner with one AlSe5 trigonal bipyramid, corners with two MgSe5 trigonal bipyramids, and a cornercorner with one MgSe4 trigonal pyramid. There are a spread of Al–Se bond distances ranging from 2.39–2.46 Å. In the fifth Al3+ site, Al3+ is bonded to five Se2- atoms to form distorted AlSe5 trigonal bipyramids that share a cornercorner with one MgSe4 tetrahedra, corners with two AlSe4 tetrahedra, a cornercorner with one MgSe5 trigonal bipyramid, a cornercorner with one MgSe4 trigonal pyramid, and an edgeedge with one MgSe4 trigonal pyramid. There are a spread of Al–Se bond distances ranging from 2.38–2.85 Å. In the sixth Al3+ site, Al3+ is bonded to five Se2- atoms to form AlSe5 trigonal bipyramids that share a cornercorner with one MgSe5 square pyramid, a cornercorner with one MgSe4 tetrahedra, a cornercorner with one AlSe4 tetrahedra, a cornercorner with one MgSe5 trigonal bipyramid, an edgeedge with one MgSe5 square pyramid, and an edgeedge with one MgSe5 trigonal bipyramid. There are a spread of Al–Se bond distances ranging from 2.43–2.66 Å. In the seventh Al3+ site, Al3+ is bonded to four Se2- atoms to form AlSe4 tetrahedra that share a cornercorner with one MgSe5 square pyramid, corners with two AlSe5 trigonal bipyramids, and a cornercorner with one MgSe4 trigonal pyramid. There are a spread of Al–Se bond distances ranging from 2.37–2.51 Å. In the eighth Al3+ site, Al3+ is bonded to four Se2- atoms to form distorted AlSe4 tetrahedra that share a cornercorner with one MgSe4 tetrahedra, a cornercorner with one AlSe5 trigonal bipyramid, a cornercorner with one MgSe4 trigonal pyramid, and an edgeedge with one MgSe5 trigonal bipyramid. There are a spread of Al–Se bond distances ranging from 2.38–2.46 Å. There are thirty-two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 2-coordinate geometry to two Mg2+, one Al3+, and one Se2- atom. The Se–Se bond length is 2.45 Å. In the second Se2- site, Se2- is bonded in a 4-coordinate geometry to two Mg2+ and two Al3+ atoms. In the third Se2- site, Se2- is bonded in a 5-coordinate geometry to four Mg2+ and one Al3+ atom. In the fourth Se2- site, Se2- is bonded in a distorted T-shaped geometry to two Mg2+ and one Al3+ atom. In the fifth Se2- site, Se2- is bonded in a 5-coordinate geometry to four Mg2+ and one Al3+ atom. In the sixth Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to three Mg2+ and one Al3+ atom. In the seventh Se2- site, Se2- is bonded to three Mg2+ and one Al3+ atom to form distorted SeMg3Al trigonal pyramids that share a cornercorner with one SeMg3Al tetrahedra and a cornercorner with one SeMg2Al2 trigonal pyramid. In the eighth Se2- site, Se2- is bonded in a distorted trigonal non-coplanar geometry to two Mg2+ and one Al3+ atom. In the ninth Se2- site, Se2- is bonded in a distorted T-shaped geometry to two Mg2+ and one Al3+ atom. In the tenth Se2- site, Se2- is bonded in a distorted L-shaped geometry to two Mg2+ atoms. In the eleventh Se2- site, Se2- is bonded in a 1-coordinate geometry to one Mg2+, one Al3+, and one Se2- atom. In the twelfth Se2- site, Se2- is bonded in a 4-coordinate geometry to four Mg2+ atoms. In the thirteenth Se2- site, Se2- is bonded to three Mg2+ and one Al3+ atom to form distorted corner-sharing SeMg3Al tetrahedra. In the fourteenth Se2- site, Se2- is bonded in a 4-coordinate geometry to three Mg2+ and one Al3+ atom. In the fifteenth Se2- site, Se2- is bonded in a 4-coordinate geometry to two Mg2+ and two Al3+ atoms. In the sixteenth Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to two Mg2+ and two Al3+ atoms. In the seventeenth Se2- site, Se2- is bonded in a 5-coordinate geometry to three Mg2+ and two Al3+ atoms. In the eighteenth Se2- site, Se2- is bonded in a distorted T-shaped geometry to two Mg2+ and one Al3+ atom. In the nineteenth Se2- site, Se2- is bonded in a 4-coordinate geometry to three Mg2+ and one Al3+ atom. In the twentieth Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to three Mg2+ and one Al3+ atom. In the twenty-first Se2- site, Se2- is bonded in a distorted see-saw-like geometry to three Mg2+ and one Al3+ atom. In the twenty-second Se2- site, Se2- is bonded in a distorted trigonal non-coplanar geometry to two Mg2+ and one Al3+ atom. In the twenty-third Se2- site, Se2- is bonded in a 4-coordinate geometry to three Mg2+ and one Al3+ atom. In the twenty-fourth Se2- site, Se2- is bonded in a 3-coordinate geometry to two Mg2+ and one Al3+ atom. In the twenty-fifth Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to three Mg2+ and one Al3+ atom. In the twenty-sixth Se2- site, Se2- is bonded in a 2-coordinate geometry to three Mg2+ and one Al3+ atom. In the twenty-seventh Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to four Mg2+ atoms. In the twenty-eighth Se2- site, Se2- is bonded in a distorted T-shaped geometry to two Mg2+ and one Al3+ atom. In the twenty-ninth Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to three Mg2+ and one Al3+ atom. In the thirtieth Se2- site, Se2- is bonded in a distorted see-saw-like geometry to three Mg2+ and one Al3+ atom. In the thirty-first Se2- site, Se2- is bonded to two Mg2+ and two Al3+ atoms to form distorted corner-sharing SeMg2Al2 trigonal pyramids. In the thirty-second Se2- site, Se2- is bonded in a 4-coordinate geometry to three Mg2+ and two Al3+ atoms.