DOI: 10.17188/1701696
title: Materials Data on MgO by Materials Project

description: MgO crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are twelve inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to four O2- atoms to form distorted MgO4 tetrahedra that share corners with five MgO4 tetrahedra, corners with three MgO5 trigonal bipyramids, corners with two equivalent MgO4 trigonal pyramids, and edges with two equivalent MgO5 trigonal bipyramids. There are a spread of Mg–O bond distances ranging from 1.96–2.06 Å. In the second Mg2+ site, Mg2+ is bonded to four O2- atoms to form MgO4 trigonal pyramids that share a cornercorner with one MgO4 tetrahedra, corners with three MgO5 trigonal bipyramids, corners with four MgO4 trigonal pyramids, and edges with two equivalent MgO5 trigonal bipyramids. There are a spread of Mg–O bond distances ranging from 1.96–2.09 Å. In the third Mg2+ site, Mg2+ is bonded to four O2- atoms to form MgO4 tetrahedra that share corners with three MgO4 tetrahedra, corners with four MgO4 trigonal pyramids, and edges with two equivalent MgO5 trigonal bipyramids. There are three shorter (1.98 Å) and one longer (2.02 Å) Mg–O bond lengths. In the fourth Mg2+ site, Mg2+ is bonded in a see-saw-like geometry to four O2- atoms. There are a spread of Mg–O bond distances ranging from 1.96–2.03 Å. In the fifth Mg2+ site, Mg2+ is bonded to five O2- atoms to form MgO5 trigonal bipyramids that share corners with two equivalent MgO4 tetrahedra, corners with four MgO5 trigonal bipyramids, corners with two MgO4 trigonal pyramids, an edgeedge with one MgO4 tetrahedra, and edges with five MgO5 trigonal bipyramids. There are a spread of Mg–O bond distances ranging from 2.04–2.20 Å. In the sixth Mg2+ site, Mg2+ is bonded to five O2- atoms to form MgO5 trigonal bipyramids that share corners with three MgO4 tetrahedra, corners with five MgO5 trigonal bipyramids, edges with three MgO5 trigonal bipyramids, and edges with two equivalent MgO4 trigonal pyramids. There are a spread of Mg–O bond distances ranging from 2.02–2.18 Å. In the seventh Mg2+ site, Mg2+ is bonded to five O2- atoms to form MgO5 trigonal bipyramids that share corners with two equivalent MgO4 tetrahedra, corners with four MgO5 trigonal bipyramids, corners with three MgO4 trigonal pyramids, and edges with two MgO5 trigonal bipyramids. There are a spread of Mg–O bond distances ranging from 2.05–2.18 Å. In the eighth Mg2+ site, Mg2+ is bonded to four O2- atoms to form MgO4 trigonal pyramids that share corners with four MgO4 tetrahedra, a cornercorner with one MgO5 trigonal bipyramid, corners with two equivalent MgO4 trigonal pyramids, and edges with three MgO5 trigonal bipyramids. There are a spread of Mg–O bond distances ranging from 1.95–2.13 Å. In the ninth Mg2+ site, Mg2+ is bonded to four O2- atoms to form MgO4 trigonal pyramids that share corners with two equivalent MgO4 tetrahedra, a cornercorner with one MgO5 trigonal bipyramid, corners with four MgO4 trigonal pyramids, and an edgeedge with one MgO5 trigonal bipyramid. There are a spread of Mg–O bond distances ranging from 1.96–2.09 Å. In the tenth Mg2+ site, Mg2+ is bonded to five O2- atoms to form MgO5 trigonal bipyramids that share a cornercorner with one MgO4 tetrahedra, corners with four MgO5 trigonal bipyramids, edges with four MgO4 tetrahedra, an edgeedge with one MgO5 trigonal bipyramid, and an edgeedge with one MgO4 trigonal pyramid. There are a spread of Mg–O bond distances ranging from 1.97–2.24 Å. In the eleventh Mg2+ site, Mg2+ is bonded to five O2- atoms to form MgO5 trigonal bipyramids that share corners with two equivalent MgO4 tetrahedra, corners with three MgO5 trigonal bipyramids, edges with three MgO5 trigonal bipyramids, and edges with three MgO4 trigonal pyramids. There are a spread of Mg–O bond distances ranging from 2.00–2.21 Å. In the twelfth Mg2+ site, Mg2+ is bonded to four O2- atoms to form distorted MgO4 tetrahedra that share corners with four MgO4 tetrahedra, corners with seven MgO5 trigonal bipyramids, a cornercorner with one MgO4 trigonal pyramid, and an edgeedge with one MgO5 trigonal bipyramid. There are a spread of Mg–O bond distances ranging from 1.99–2.05 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded to five Mg2+ atoms to form OMg5 trigonal bipyramids that share corners with two equivalent OMg4 tetrahedra, corners with four OMg5 trigonal bipyramids, corners with three OMg4 trigonal pyramids, and edges with two OMg5 trigonal bipyramids. In the second O2- site, O2- is bonded to four Mg2+ atoms to form OMg4 trigonal pyramids that share corners with seven OMg4 trigonal pyramids and edges with two equivalent OMg5 trigonal bipyramids. In the third O2- site, O2- is bonded to five Mg2+ atoms to form OMg5 trigonal bipyramids that share corners with two equivalent OMg4 tetrahedra, corners with five OMg5 trigonal bipyramids, a cornercorner with one OMg4 trigonal pyramid, edges with three OMg5 trigonal bipyramids, and edges with two equivalent OMg4 trigonal pyramids. In the fourth O2- site, O2- is bonded in a see-saw-like geometry to four Mg2+ atoms. In the fifth O2- site, O2- is bonded to four Mg2+ atoms to form OMg4 trigonal pyramids that share a cornercorner with one OMg4 tetrahedra, corners with three OMg5 trigonal bipyramids, corners with four OMg4 trigonal pyramids, and edges with two equivalent OMg5 trigonal bipyramids. In the sixth O2- site, O2- is bonded to four Mg2+ atoms to form distorted OMg4 trigonal pyramids that share corners with two equivalent OMg4 tetrahedra, corners with three OMg5 trigonal bipyramids, corners with five OMg4 trigonal pyramids, and edges with two equivalent OMg5 trigonal bipyramids. In the seventh O2- site, O2- is bonded to four Mg2+ atoms to form OMg4 trigonal pyramids that share a cornercorner with one OMg5 trigonal bipyramid, corners with six OMg4 trigonal pyramids, and edges with three OMg5 trigonal bipyramids. In the eighth O2- site, O2- is bonded to five Mg2+ atoms to form OMg5 trigonal bipyramids that share corners with four OMg5 trigonal bipyramids, corners with four OMg4 trigonal pyramids, an edgeedge with one OMg4 tetrahedra, and edges with five OMg5 trigonal bipyramids. In the ninth O2- site, O2- is bonded to four Mg2+ atoms to form OMg4 trigonal pyramids that share a cornercorner with one OMg5 trigonal bipyramid, corners with six OMg4 trigonal pyramids, and an edgeedge with one OMg5 trigonal bipyramid. In the tenth O2- site, O2- is bonded to four Mg2+ atoms to form distorted OMg4 tetrahedra that share corners with two equivalent OMg4 tetrahedra, corners with seven OMg5 trigonal bipyramids, corners with three OMg4 trigonal pyramids, and an edgeedge with one OMg5 trigonal bipyramid. In the eleventh O2- site, O2- is bonded to five Mg2+ atoms to form OMg5 trigonal bipyramids that share a cornercorner with one OMg4 tetrahedra, corners with four OMg5 trigonal bipyramids, an edgeedge with one OMg5 trigonal bipyramid, and edges with five OMg4 trigonal pyramids. In the twelfth O2- site, O2- is bonded to five Mg2+ atoms to form OMg5 trigonal bipyramids that share corners with two equivalent OMg4 tetrahedra, corners with three OMg5 trigonal bipyramids, edges with three OMg5 trigonal bipyramids, and edges with three OMg4 trigonal pyramids.