Mg6AlCrO8
High-Entropy Materials HEAMP-ID: mp-1033034 · Space group: P4/mmm (#123)
Basic Information
Formula
Mg6AlCrO8
MP-ID
mp-1033034
Elements
4
Sites
16
Density
3.6425
g/cm³
Volume
160.84
ų
Cell a
8.8047
Å
Cell b
4.2740
Å
Cell c
4.2740
Å
α Angle
90.00
°
β Angle
90.00
°
γ Angle
90.00
°
Space Group
P4/mmm
Point Group
4/mmm
Crystal System
Tetragonal
Bravais Lattice
tP
Stability
No
Packing Fraction
-
X-ray Diffraction
Diffraction Pattern
X-axis: 2θ (°); Y-axis: relative intensity; Cu Kα ; λ=1.5418 Å
Diffraction Peaks (Top 20)
| 2θ | d (Å) | I | hkl |
|---|---|---|---|
| 10.05 | 8.8047 | 12.3 | (1,0,0) |
| 20.17 | 4.4024 | 3.0 | (2,0,0) |
| 20.78 | 4.2740 | 3.7 | (0,1,0) |
| 23.13 | 3.8449 | 2.4 | (1,1,0) |
| 29.12 | 3.0665 | 3.1 | (2,1,0) |
| 29.56 | 3.0222 | 1.9 | (0,1,1) |
| 31.29 | 2.8585 | 3.5 | (1,1,1) |
| 36.05 | 2.4916 | 27.0 | (2,1,1) |
| 37.16 | 2.4194 | 6.1 | (3,1,0) |
| 41.00 | 2.2012 | 52.5 | (4,0,0) |
| 42.29 | 2.1370 | 100.0 | (0,2,0) |
| 43.58 | 2.0767 | 1.1 | (1,2,0) |
| 47.28 | 1.9225 | 1.0 | (2,2,0) |
| 57.54 | 1.6017 | 2.5 | (3,2,1) |
| 60.37 | 1.5333 | 57.0 | (4,2,0) |
| 61.35 | 1.5111 | 28.2 | (0,2,2) |
| 71.46 | 1.3201 | 6.4 | (6,1,1) |
| 73.26 | 1.2920 | 9.9 | (2,3,1) |
| 76.46 | 1.2458 | 25.4 | (4,2,2) |
| 88.93 | 1.1006 | 3.7 | (8,0,0) |
Energy Properties
Formation Energy/atom
-2.70792
eV/atom
Energy/atom
-6.63074
eV/atom
Energy above Hull
0.2465
eV/atom
Uncorrected Energy
-6.1623
eV/atom
Volume/atom
10.05
ų
c/a Ratio
0.4854
Electronic Properties
Metallic
Metal
Band Gap
0
eV
Direct Gap
No
CBM
N/A
eV
Magnetic Properties
Magnetic
Yes
Total Mag. Moment
4.5502
μB
Mag. Ordering
FM
Mag. Sites
1
Magnetization/Volume
0.028290
μB/ų
Elastic Properties
Elastic data not available
Feature Analysis
Composition Overview
Element Composition (atomic fraction)
Composition Info
Major / Matrix Element
O · 0.500
Element Family
Metalloid-Nonmetal
Solute Fraction
0.500
Interstitial Fraction
0.000
High-Entropy Alloy Features
Composite Radar (normalized)
Element-Class Share
Mix Entropy ΔS/R
1.0610
HEA criterion (>1.0 = high entropy)
Mix Entropy ΔS
8.8208
J/mol·K
Ω Parameter
2.9794
Ω > 1.1 favors solid solution
Atomic Size Mismatch δr
44.519%
δr < 6.6% favors single-phase solid solution
Electronegativity Diff Δχ
1.0292
smaller = more stable mixing
VEC
3.313
valence electron concentration, affects phase stability
Mix Enthalpy ΔH_mix
-1.682
kJ/mol; negative = exothermic mixing
Entropy Norm
0.7653
SS Former
0
Phase Tendency
IM
Related Tasks
Citation & References
Materials Project Page
https://materialsproject.org/materials/mp-1033034
Reference Citation
The crystal structure and related material properties of Mg6AlCrO8 were obtained from the Materials Project database (MP-ID: mp-1033034, database version v2026.04.13).
Literature Citation
Horton, M.K., Huck, P., Yang, R.X. et al. Accelerated data-driven materials science with the Materials Project. Nat. Mater. 24, 1522–1532 (2025). https://doi.org/10.1038/s41563-025-02272-0
3D Crystal Structure Rendering
Loading 3D structure…
Style: Ball & Stick
|
Drag to rotate · Scroll to zoom · Right-click to pan
Raw CIF Data
# generated using pymatgen
data_Mg6AlCrO8
_symmetry_space_group_name_H-M 'P 1'
_cell_length_a 8.80473884
_cell_length_b 4.27397779
_cell_length_c 4.27397779
_cell_angle_alpha 90.00000000
_cell_angle_beta 90.00000000
_cell_angle_gamma 90.00000000
_symmetry_Int_Tables_number 1
_chemical_formula_structural Mg6AlCrO8
_chemical_formula_sum 'Mg6 Al1 Cr1 O8'
_cell_volume 160.83516197
_cell_formula_units_Z 1
loop_
_symmetry_equiv_pos_site_id
_symmetry_equiv_pos_as_xyz
1 'x, y, z'
loop_
_atom_site_type_symbol
_atom_site_label
_atom_site_symmetry_multiplicity
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
Mg Mg0 1 0.50000000 0.00000000 0.00000000 1.0
Mg Mg1 1 0.50000000 0.50000000 0.50000000 1.0
Mg Mg2 1 0.25101473 0.00000000 0.50000000 1.0
Mg Mg3 1 0.74898527 0.00000000 0.50000000 1.0
Mg Mg4 1 0.25101473 0.50000000 0.00000000 1.0
Mg Mg5 1 0.74898527 0.50000000 0.00000000 1.0
Al Al6 1 0.00000000 0.00000000 0.00000000 1.0
Cr Cr7 1 0.00000000 0.50000000 0.50000000 1.0
O O8 1 0.22692648 0.00000000 0.00000000 1.0
O O9 1 0.77307352 0.00000000 0.00000000 1.0
O O10 1 0.26930638 0.50000000 0.50000000 1.0
O O11 1 0.73069362 0.50000000 0.50000000 1.0
O O12 1 0.00000000 0.00000000 0.50000000 1.0
O O13 1 0.50000000 0.00000000 0.50000000 1.0
O O14 1 0.00000000 0.50000000 0.00000000 1.0
O O15 1 0.50000000 0.50000000 0.00000000 1.0
