Ba2AlCr3O7

High-Entropy Materials HEA

MP-ID: mp-1048330 · Space group: Pmmm (#47)

Materials Project API

Basic Information

Formula

Ba2AlCr3O7

MP-ID

mp-1048330

Elements

Sites

Density

5.3812

g/cm³

Volume

175.77

Å³

Cell a

3.8263

Cell b

3.9681

Cell c

11.5769

α Angle

90.00

β Angle

90.00

γ Angle

90.00

Space Group

Pmmm

Point Group

mmm

Crystal System

Orthorhombic

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
7.64	11.5769	10.1	(0,0,1)
15.31	5.7884	20.6	(0,0,2)
22.41	3.9681	9.0	(0,1,0)
23.05	3.8590	8.8	(0,0,3)
23.25	3.8263	3.6	(1,0,0)
23.70	3.7537	12.4	(0,1,1)
24.50	3.6330	4.4	(1,0,1)
27.25	3.2729	21.5	(0,1,2)
27.95	3.1920	30.8	(1,0,2)
30.90	2.8942	2.7	(0,0,4)
32.36	2.7665	87.1	(0,1,3)
32.51	2.7544	100.0	(1,1,0)
32.97	2.7171	98.8	(1,0,3)
33.44	2.6796	14.4	(1,1,1)
36.11	2.4872	27.1	(1,1,2)
38.50	2.3383	2.5	(0,1,4)
38.90	2.3154	30.5	(0,0,5)
40.23	2.2419	28.2	(1,1,3)
45.35	1.9998	3.0	(0,1,5)
45.73	1.9841	36.2	(0,2,0)
45.81	1.9809	1.5	(1,0,5)
47.10	1.9295	12.4	(0,0,6)
47.53	1.9131	32.0	(2,0,0)
48.50	1.8769	2.4	(0,2,2)

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Energy Properties

Formation Energy/atom

-2.32895

eV/atom

Energy/atom

-7.80421

eV/atom

Energy above Hull

0.3824

eV/atom

Uncorrected Energy

-6.9730

eV/atom

Volume/atom

13.52

Å³

c/a Ratio

3.0256

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

10.9981

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.062570

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

O · 0.538

Element Family

Metalloid-Nonmetal

Solute Fraction

0.462

Interstitial Fraction

0.000

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

1.1570

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

9.6192

J/mol·K

Ω Parameter

10.2719

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

53.274%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

1.0480

smaller = more stable mixing

VEC

4.077

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-0.710

kJ/mol; negative = exothermic mixing

Entropy Norm

0.8346

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (3)

aaachqvo aaadvgsc aaaeakfa

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-1048330

Reference Citation

The crystal structure and related material properties of Ba2AlCr3O7 were obtained from the Materials Project database (MP-ID: mp-1048330, 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_Ba2AlCr3O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.82627000
_cell_length_b   3.96811500
_cell_length_c   11.57688900
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   90.00000000
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ba2AlCr3O7
_chemical_formula_sum   'Ba2 Al1 Cr3 O7'
_cell_volume   175.77282467
_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  0.31486000  1.0
  Ba  Ba1  1  0.50000000  0.50000000  0.68514000  1.0
  Al  Al2  1  0.50000000  0.50000000  0.00000000  1.0
  Cr  Cr3  1  0.00000000  0.00000000  0.13925100  1.0
  Cr  Cr4  1  0.00000000  0.00000000  0.86074900  1.0
  Cr  Cr5  1  0.00000000  0.00000000  0.50000000  1.0
  O  O6  1  0.00000000  0.50000000  0.50000000  1.0
  O  O7  1  0.50000000  0.00000000  0.10703900  1.0
  O  O8  1  0.50000000  0.00000000  0.89296100  1.0
  O  O9  1  0.00000000  0.50000000  0.10738400  1.0
  O  O10  1  0.00000000  0.50000000  0.89261600  1.0
  O  O11  1  0.00000000  0.00000000  0.32022000  1.0
  O  O12  1  0.00000000  0.00000000  0.67978000  1.0

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