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All sourcesNASA NTRSDOE OSTI
NASA NTRS1983

Phenomenological in-situ TEM gas exposure studies of palladium particles on MgO at room temperature

It has been found that very small vapor-deposited catalytically active metal particles in the 1-2 nm size range on metal oxide substrates can undergo significant changes when they are exposed to gases such as oxygen or air, or even when allowed to 'anneal' at room temperature (RT) under vacuum conditions. The present investigation is concerned with continued in-situ gas exposures of as-deposited, 1 to 2 nm size palladium particles on MgO to air, oxygen, nitrogen, hydrogen, CO, and water vapor at RT. It is found that the low-pressure exposure to various gases at RT can significantly affect small palladium particles supported on MgO surfaces. Exposure to oxygen for 3 min at 0.0002 m bar produces a considerable amount of coalescence, flattening of the particles, and some distinct crystallographic particle shapes.

Heinemann, K.↗
NASA NTRS1988

The effect of Al2O3, CaO, Cr2O3 and MgO on devitrification of silica

The effect of doping on devitrification of vitreous silica was studied at 1100, 1200, and 1300 C. Dispersion of dopants on a molecular scale was accomplished via a sol-gel technique. All dopants accelerated the devitrification of silica but to different degrees. The most active was CaO followed by MgO, Al2O3, and Cr2O3. Pure silica and silica containing Cr2O3 and Al2O3 devitrified to alpha-cristobalite only, whereas silica doped with CaO and MgO produced alpha-quartz and alpha-cristobalite. It appears that prolonged heat treatment would cause alpha-quartz to transform to alpha-cristobalite.

Zaplatynsky, Isidor↗
NASA NTRS1994

A Redetermination of the Dissociation Energy of MgO(+)

In 1986, we reported a dissociation energy (D(sub 0) of 2.31 eV for the X(sup 2)Pi ground state of MgO(+). This value was determined by computing the dissociation energy to the Mg(2+) + O(-) limit and adjusting the value to the Mg(+) + O limit using the experimental Ionization Potential (IP) of Mg(+) and the Electron Affinity (EA) of O. The success of this method relies on the assumption that there is little covalent contribution to the bonding. The very small (0.04 eV) correlation contribution to the binding energy was taken as corroboration for the validity of this approach. Our earlier theoretical value was estimated to be accurate to at least 0.2 eV. It is in excellent agreement with the subsequent value of 2.30 +/- 0.13 eV determined by Freiser and co-workers from photodissociation experiments. It is also consistent with the upper (less than 3.1 eV) and lower (greater than 1.1 eV) bounds determined by Rowe obtained by studying the reactions of Mg(+) with 03 and NO2. However, it is inconsistent with an upper bound of 1.7 eV reported by Kappes and Staley based on their failure to observe MgO(+) in the reaction of Mg(+) with N2O. The picture became somewhat clouded, however, by the recent guided-ion beam mass spectrometric studies of Dalleska and Armentrout. Their initial analysis of the reaction data for Mg(+) + O2 lead to a bond dissociation energy of 2.92 +/- 0.25 eV, which is considerably larger than the value of 2.47 +/- 0.06 eV deduced from their studies of the Mg(+)+NO2 reaction.

Bauschlicher, Charles W., Jr.↗
NASA NTRS1997

Annealing Effects on the Surface Plasmon of MgO Implanted with Gold

Gold ion implantation was carried out with the energy of 1.1 MeV into (100) oriented MgO single crystal. Implanted doses are 1, 3, 6, 10 x 10(exp 16) ions/sq cm. The gold irradiation results in the formation of gold ion implanted layer with a thickness of 0.2 microns and defect formation. In order to form gold colloids from the as-implanted samples, we annealed the gold implanted MgO samples in three kinds of atmospheres: (1)Ar only, (2)H2 and Ar, and (3)O2 and Ar. The annealing over 1200 C enhanced the gold colloid formation which shows surface plasmon resonance band of gold. The surface plasmon bands of samples annealed in three kinds of atmospheres were found to be at 535 nm (Ar only), 524 nm(H2+Ar), and 560 nm (02+Ar), The band positions of surface plasmon can be reversibly changed by an additional annealing.

Ueda, A.↗
NASA NTRS2001

On Interpreting the Photoelectron Spectra of MgO

The (sup 2)Sigma(+) and (sup 2)Pi states of MgO(-) and the (sup 1)Sigma(+), (sup 1)Pi, and (sup 3)Pi states of MgO are studied using the averaged coupled-pair functional (ACPF) approach. The computed spectroscopic constants are in good agreement with the available experimental data. The computed Franck-Condon factors and photodetachment overlaps are compared with experiment.

Bauschlicher, Charles W., Jr.↗
NASA NTRS2017

Metastable Phase Relations in the System Ca(sub O)-Al2(sub O)3-MgO-TiO(sub 2): Applications to Ca- And Al-Rich Inclusions

Introduction: High temperature phases such as corundum, hibonite, grossite, and perovskite are among the earliest phases that condensed in the early solar nebula. Recent work has shown that defect-structured phases occur in some ultrarefractory inclusions as metastable, possibly more kinetically-favored alternatives to the thermodynamically predicted stable phase assemblages [1-4]. For example, Han et al. have shown that non-stoichiometry in hibonite is accommodated by extra "spinel" blocks in the structure instead of the equilibrium assemblages hibonite+corundum or hibonite+spinel. To explore these relations, we have conducted a series of experiments in the system CaO-Al2O3- MgO-TiO2. Here we discuss the compositions and mineralogy of the experimental samples and how they relate to phases in refractory inclusions with a focus on perovskite and spinel. Methods: For the series of annealing studies, a CaO-Al2O3 eutectic melt is allowed to react with a pure alumina crucible at 1,530degC for either 4 hours or 5 days, followed by quenching in air. Later experiments were similar except that additions of 5 wt% MgO, and CaTiO(sub 3) were used to explore the effect of minor elements on the phase assemblages. The experimental conditions resulted in reaction zones approximately 100-300 m wide consisting of a hibonite layer immediately adjacent to the corundum, followed by a grossite layer, and finally krotite with residual quenched melt. For the experiments with Mg, spinel is distributed in all layers but is mainly concentrated in the krotite layer. In the Ti-bearing experiments, perovskite precipitated in association with the krotite and residual melt. In addition to the experiments, we also analyzed perovskite grains in the FUN inclusion SHAL [5] and a large compact type A CAI from Allende. The experiments and refractory inclusions were analyzed using a JEOL 7600F SEM and quantitative analyses were obtained using the JEOL 8530F field-emission electron microprobe.

Keller, L. P.↗
DOE OSTI2020

Materials Data on MgO by Materials Project

MgO is Halite, Rock Salt structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. Mg2+ is bonded to six equivalent O2- atoms to form a mixture of edge and corner-sharing MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. All Mg–O bond lengths are 2.13 Å. O2- is bonded to six equivalent Mg2+ atoms to form a mixture of edge and corner-sharing OMg6 octahedra. The corner-sharing octahedral tilt angles are 0°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on MgO by Materials Project

MgO is Wurtzite structured and crystallizes in the hexagonal P6_3mc space group. The structure is three-dimensional. Mg2+ is bonded to four equivalent O2- atoms to form corner-sharing MgO4 tetrahedra. There are three shorter (1.99 Å) and one longer (2.02 Å) Mg–O bond lengths. O2- is bonded to four equivalent Mg2+ atoms to form corner-sharing OMg4 tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on MgO by Materials Project

MgO is Moissanite-4H-like structured and crystallizes in the trigonal P3m1 space group. The structure is three-dimensional. there are six inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to four O2- atoms to form corner-sharing MgO4 tetrahedra. There is three shorter (1.99 Å) and one longer (2.00 Å) Mg–O bond length. In the second Mg2+ site, Mg2+ is bonded to four O2- atoms to form corner-sharing MgO4 tetrahedra. There is one shorter (1.99 Å) and three longer (2.00 Å) Mg–O bond length. In the third Mg2+ site, Mg2+ is bonded to four O2- atoms to form corner-sharing MgO4 tetrahedra. All Mg–O bond lengths are 1.99 Å. In the fourth Mg2+ site, Mg2+ is bonded to four O2- atoms to form corner-sharing MgO4 tetrahedra. There are three shorter (2.00 Å) and one longer (2.02 Å) Mg–O bond lengths. In the fifth Mg2+ site, Mg2+ is bonded to four O2- atoms to form corner-sharing MgO4 tetrahedra. There are three shorter (2.00 Å) and one longer (2.02 Å) Mg–O bond lengths. In the sixth Mg2+ site, Mg2+ is bonded to four O2- atoms to form corner-sharing MgO4 tetrahedra. All Mg–O bond lengths are 2.00 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded to four Mg2+ atoms to form corner-sharing OMg4 tetrahedra. In the second O2- site, O2- is bonded to four Mg2+ atoms to form corner-sharing OMg4 tetrahedra. In the third O2- site, O2- is bonded to four Mg2+ atoms to form corner-sharing OMg4 tetrahedra. In the fourth O2- site, O2- is bonded to four Mg2+ atoms to form corner-sharing OMg4 tetrahedra. In the fifth O2- site, O2- is bonded to four Mg2+ atoms to form corner-sharing OMg4 tetrahedra. In the sixth O2- site, O2- is bonded to four Mg2+ atoms to form corner-sharing OMg4 tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on MgO by Materials Project

MgO is Moissanite-4H structured and crystallizes in the hexagonal P6_3mc space group. The structure is three-dimensional. there are two inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to four O2- atoms to form corner-sharing MgO4 tetrahedra. There is one shorter (1.99 Å) and three longer (2.00 Å) Mg–O bond length. In the second Mg2+ site, Mg2+ is bonded to four O2- atoms to form corner-sharing MgO4 tetrahedra. There are three shorter (2.00 Å) and one longer (2.01 Å) Mg–O bond lengths. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to four Mg2+ atoms to form corner-sharing OMg4 tetrahedra. In the second O2- site, O2- is bonded to four Mg2+ atoms to form corner-sharing OMg4 tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on MgO by Materials Project

MgO is Tetraauricupride structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Mg2+ is bonded in a body-centered cubic geometry to eight equivalent O2- atoms. All Mg–O bond lengths are 2.30 Å. O2- is bonded in a body-centered cubic geometry to eight equivalent Mg2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on MgO by Materials Project

MgO is Tungsten Carbide structured and crystallizes in the hexagonal P-6m2 space group. The structure is three-dimensional. Mg2+ is bonded to six equivalent O2- atoms to form a mixture of distorted edge, face, and corner-sharing MgO6 pentagonal pyramids. All Mg–O bond lengths are 2.16 Å. O2- is bonded to six equivalent Mg2+ atoms to form a mixture of distorted edge, face, and corner-sharing OMg6 pentagonal pyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on MgO by Materials Project

MgO crystallizes in the orthorhombic Ibam space group. The structure is three-dimensional. there are three inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to five O2- atoms to form a mixture of edge and corner-sharing MgO5 trigonal bipyramids. There are a spread of Mg–O bond distances ranging from 2.02–2.11 Å. In the second Mg2+ site, Mg2+ is bonded to five O2- atoms to form a mixture of edge and corner-sharing MgO5 trigonal bipyramids. There are a spread of Mg–O bond distances ranging from 2.03–2.11 Å. In the third Mg2+ site, Mg2+ is bonded to five O2- atoms to form a mixture of edge and corner-sharing MgO5 trigonal bipyramids. There are a spread of Mg–O bond distances ranging from 2.01–2.11 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded to five Mg2+ atoms to form a mixture of edge and corner-sharing OMg5 trigonal bipyramids. In the second O2- site, O2- is bonded to five Mg2+ atoms to form a mixture of edge and corner-sharing OMg5 trigonal bipyramids. In the third O2- site, O2- is bonded to five Mg2+ atoms to form a mixture of edge and corner-sharing OMg5 trigonal bipyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on MgO by Materials Project

MgO is Molybdenum Carbide MAX Phase-like structured and crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are four inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to six O2- atoms to form a mixture of distorted corner and edge-sharing MgO6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 2°. All Mg–O bond lengths are 2.17 Å. In the second Mg2+ site, Mg2+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. All Mg–O bond lengths are 2.12 Å. In the third Mg2+ site, Mg2+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. All Mg–O bond lengths are 2.12 Å. In the fourth Mg2+ site, Mg2+ is bonded to six equivalent O2- atoms to form a mixture of corner and edge-sharing MgO6 octahedra. All Mg–O bond lengths are 2.12 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to six equivalent Mg2+ atoms to form a mixture of corner and edge-sharing OMg6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the second O2- site, O2- is bonded to six Mg2+ atoms to form a mixture of corner and edge-sharing OMg6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the third O2- site, O2- is bonded to six Mg2+ atoms to form a mixture of corner, edge, and face-sharing OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–47°. In the fourth O2- site, O2- is bonded to six Mg2+ atoms to form a mixture of corner, edge, and face-sharing OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–47°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on MgO by Materials Project

MgO crystallizes in the hexagonal P6/mcc space group. The structure is three-dimensional. Mg2+ is bonded to five equivalent O2- atoms to form a mixture of corner and edge-sharing MgO5 trigonal bipyramids. There are a spread of Mg–O bond distances ranging from 2.01–2.10 Å. O2- is bonded to five equivalent Mg2+ atoms to form a mixture of corner and edge-sharing OMg5 trigonal bipyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on MgO by Materials Project

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.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on MgO by Materials Project

MgO crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are three inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to four O2- atoms to form a mixture of edge and corner-sharing MgO4 trigonal pyramids. There are a spread of Mg–O bond distances ranging from 1.95–2.09 Å. In the second Mg2+ site, Mg2+ is bonded in a distorted see-saw-like geometry to four O2- atoms. There are a spread of Mg–O bond distances ranging from 1.95–2.03 Å. In the third Mg2+ site, Mg2+ is bonded to four O2- atoms to form a mixture of edge and corner-sharing MgO4 trigonal pyramids. There are a spread of Mg–O bond distances ranging from 1.95–2.08 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded to four Mg2+ atoms to form a mixture of edge and corner-sharing OMg4 trigonal pyramids. In the second O2- site, O2- is bonded in a distorted see-saw-like geometry to four Mg2+ atoms. In the third O2- site, O2- is bonded to four Mg2+ atoms to form a mixture of edge and corner-sharing OMg4 trigonal pyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on MgO by Materials Project

MgO crystallizes in the orthorhombic Ibam space group. The structure is three-dimensional. there are two inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to five O2- atoms to form a mixture of corner and edge-sharing MgO5 trigonal bipyramids. There are a spread of Mg–O bond distances ranging from 2.03–2.11 Å. In the second Mg2+ site, Mg2+ is bonded to five O2- atoms to form a mixture of corner and edge-sharing MgO5 trigonal bipyramids. There are a spread of Mg–O bond distances ranging from 2.01–2.11 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to five Mg2+ atoms to form a mixture of corner and edge-sharing OMg5 trigonal bipyramids. In the second O2- site, O2- is bonded to five Mg2+ atoms to form a mixture of corner and edge-sharing OMg5 trigonal bipyramids.

36 MATERIALS SCIENCE↗