Ba2AlCr3O8

High-Entropy Materials HEA

MP-ID: mp-1048171 · Space group: P4/mmm (#123)

Materials Project API

Basic Information

Formula

Ba2AlCr3O8

MP-ID

mp-1048171

Elements

Sites

Density

5.4978

g/cm³

Volume

176.88

Å³

Cell a

3.8971

Cell b

3.8971

Cell c

11.6466

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

Stability

Packing Fraction

X-ray Diffraction

Diffraction Pattern

Target / Radiation

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

Diffraction Peaks (Top 24)

2θ	d (Å)	I	hkl
7.59	11.6466	28.5	(0,0,1)
15.21	5.8233	2.3	(0,0,2)
22.82	3.8971	5.6	(1,0,0)
22.91	3.8822	3.3	(0,0,3)
24.08	3.6957	12.9	(1,0,1)
27.54	3.2387	9.7	(1,0,2)
30.71	2.9117	4.9	(0,0,4)
32.49	2.7557	43.3	(1,1,0)
32.56	2.7504	100.0	(1,0,3)
33.41	2.6816	8.4	(1,1,1)
36.06	2.4908	10.1	(1,1,2)
38.60	2.3325	1.7	(1,0,4)
38.65	2.3293	7.8	(0,0,5)
40.13	2.2471	16.7	(1,1,3)
45.31	2.0014	3.0	(1,1,4)
46.61	1.9485	33.9	(2,0,0)
46.80	1.9411	9.8	(0,0,6)
47.30	1.9218	1.6	(2,0,1)
51.36	1.7789	1.8	(1,1,5)
52.51	1.7428	1.7	(2,1,0)
52.55	1.7415	1.9	(2,0,3)
52.68	1.7375	3.0	(1,0,6)
53.14	1.7236	3.1	(2,1,1)
55.00	1.6697	3.0	(2,1,2)

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Energy Properties

Formation Energy/atom

-2.43364

eV/atom

Energy/atom

-7.87124

eV/atom

Energy above Hull

0.3807

eV/atom

Uncorrected Energy

-7.0503

eV/atom

Volume/atom

12.63

Å³

c/a Ratio

2.9886

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

8.9990

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.050880

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

1.1164

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

9.2815

J/mol·K

Ω Parameter

10.7330

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

54.215%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

1.0387

smaller = more stable mixing

VEC

4.071

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-0.612

kJ/mol; negative = exothermic mixing

Entropy Norm

0.8053

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (3)

aaachqpr aaadunlp aaaeahrl

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-1048171

Reference Citation

The crystal structure and related material properties of Ba2AlCr3O8 were obtained from the Materials Project database (MP-ID: mp-1048171, 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

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Raw CIF Data

# generated using pymatgen
data_Ba2AlCr3O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.89707300
_cell_length_b   3.89707300
_cell_length_c   11.64664000
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   90.00000000
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ba2AlCr3O8
_chemical_formula_sum   'Ba2 Al1 Cr3 O8'
_cell_volume   176.87959440
_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
  Ba  Ba0  1  0.50000000  0.50000000  0.16673400  1.0
  Ba  Ba1  1  0.50000000  0.50000000  0.83326600  1.0
  Al  Al2  1  0.50000000  0.50000000  0.50000000  1.0
  Cr  Cr3  1  0.00000000  0.00000000  0.35285800  1.0
  Cr  Cr4  1  0.00000000  0.00000000  0.00000000  1.0
  Cr  Cr5  1  0.00000000  0.00000000  0.64714200  1.0
  O  O6  1  0.00000000  0.50000000  0.39230700  1.0
  O  O7  1  0.50000000  0.00000000  0.39230700  1.0
  O  O8  1  0.50000000  0.00000000  0.00000000  1.0
  O  O9  1  0.00000000  0.00000000  0.18850600  1.0
  O  O10  1  0.00000000  0.50000000  0.60769300  1.0
  O  O11  1  0.50000000  0.00000000  0.60769300  1.0
  O  O12  1  0.00000000  0.00000000  0.81149400  1.0
  O  O13  1  0.00000000  0.50000000  0.00000000  1.0

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