AlCr2O4

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-756851 · Space group: Fd-3m (#227)

Materials Project API

Basic Information

Formula

AlCr2O4

MP-ID

mp-756851

Elements

Sites

Density

4.3686

g/cm³

Volume

148.22

Å³

Cell a

5.9403

Cell b

5.9403

Cell c

5.9403

α Angle

60.00

β Angle

60.00

γ Angle

60.00

Space Group

Fd-3m

Point Group

m-3m

Crystal System

Cubic

Bravais Lattice

Stability

Packing Fraction

0.7405

X-ray Diffraction

Diffraction Pattern

Target / Radiation

X-axis: 2θ (°); Y-axis: relative intensity; Cu Kα ; λ=1.5418 Å

Diffraction Peaks (Top 17)

2θ	d (Å)	I	hkl
18.29	4.8502	41.3	(1,1,1)
30.09	2.9701	10.9	(2,1,1)
35.44	2.5329	100.0	(2,2,1)
37.07	2.4251	9.6	(2,2,2)
43.07	2.1002	53.7	(2,2,0)
47.16	1.9273	9.2	(3,2,2)
53.43	1.7148	4.1	(3,3,2)
56.96	1.6167	30.1	(3,3,3)
62.55	1.4851	56.0	(4,2,2)
65.76	1.4200	5.6	(4,3,2)
70.96	1.3283	1.7	(4,3,1)
73.99	1.2811	9.7	(4,4,3)
74.99	1.2665	5.0	(4,4,2)
78.96	1.2126	8.0	(4,4,4)
81.89	1.1764	2.7	(5,2,2)
86.74	1.1226	2.0	(5,4,3)
89.64	1.0937	17.4	(5,4,2)

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Energy Properties

Formation Energy/atom

-2.49056

eV/atom

Energy/atom

-8.61106

eV/atom

Energy above Hull

0.1419

eV/atom

Uncorrected Energy

-7.6473

eV/atom

Volume/atom

10.59

Å³

c/a Ratio

1.0000

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

14.0000

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.094450

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

O · 0.571

Element Family

Metalloid-Nonmetal

Solute Fraction

0.429

Interstitial Fraction

0.000

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

0.9557

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

7.9457

J/mol·K

Ω Parameter

3.8327

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

39.898%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.8893

smaller = more stable mixing

VEC

4.429

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-1.633

kJ/mol; negative = exothermic mixing

Entropy Norm

0.8699

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.468

Family

O-rich Multi-Component

Matrix Element

O · 0.571

Related Tasks

Related computation task IDs (3)

aaabzhob aaadcesz aaadvcok

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-756851

Reference Citation

The crystal structure and related material properties of AlCr2O4 were obtained from the Materials Project database (MP-ID: mp-756851, 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…

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Raw CIF Data

# generated using pymatgen
data_AlCr2O4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.94027113
_cell_length_b   5.94027113
_cell_length_c   5.94027113
_cell_angle_alpha   60.00000000
_cell_angle_beta   60.00000000
_cell_angle_gamma   60.00000000
_symmetry_Int_Tables_number   1
_chemical_formula_structural   AlCr2O4
_chemical_formula_sum   'Al2 Cr4 O8'
_cell_volume   148.21897519
_cell_formula_units_Z   2
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
  Al  Al0  1  0.00000000  0.00000000  0.00000000  1.0
  Al  Al1  1  0.25000000  0.25000000  0.25000000  1.0
  Cr  Cr2  1  0.62500000  0.62500000  0.62500000  1.0
  Cr  Cr3  1  0.62500000  0.62500000  0.12500000  1.0
  Cr  Cr4  1  0.62500000  0.12500000  0.62500000  1.0
  Cr  Cr5  1  0.12500000  0.62500000  0.62500000  1.0
  O  O6  1  0.87509200  0.87509200  0.37472400  1.0
  O  O7  1  0.87509200  0.37472400  0.87509200  1.0
  O  O8  1  0.37472400  0.87509200  0.87509200  1.0
  O  O9  1  0.87509200  0.87509200  0.87509200  1.0
  O  O10  1  0.37490800  0.37490800  0.37490800  1.0
  O  O11  1  0.87527600  0.37490800  0.37490800  1.0
  O  O12  1  0.37490800  0.87527600  0.37490800  1.0
  O  O13  1  0.37490800  0.37490800  0.87527600  1.0

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