Ba2AlNi3O7

High-Entropy Materials HEA

MP-ID: mp-1048483 · Space group: Pmmm (#47)

Materials Project API

Basic Information

Formula

Ba2AlNi3O7

MP-ID

mp-1048483

Elements

Sites

Density

5.8896

g/cm³

Volume

166.27

Å³

Cell a

3.7501

Cell b

3.9115

Cell c

11.3348

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
7.80	11.3348	9.3	(0,0,1)
15.64	5.6674	21.5	(0,0,2)
22.73	3.9115	3.8	(0,1,0)
23.55	3.7783	2.5	(0,0,3)
24.07	3.6975	8.6	(0,1,1)
25.01	3.5603	2.6	(1,0,1)
27.71	3.2192	19.9	(0,1,2)
28.54	3.1274	28.0	(1,0,2)
31.57	2.8337	1.8	(0,0,4)
32.96	2.7175	87.7	(0,1,3)
33.09	2.7070	100.0	(1,1,0)
33.67	2.6616	96.9	(1,0,3)
34.05	2.6330	12.0	(1,1,1)
36.79	2.4427	24.5	(1,1,2)
39.26	2.2948	3.9	(0,1,4)
39.76	2.2670	23.9	(0,0,5)
39.87	2.2608	1.8	(1,0,4)
41.02	2.2005	14.8	(1,1,3)
46.29	1.9614	4.1	(0,1,5)
46.43	1.9558	35.0	(0,2,0)
46.83	1.9400	2.4	(1,0,5)
48.17	1.8891	13.1	(0,0,6)
48.55	1.8751	30.4	(2,0,0)
49.29	1.8488	2.5	(0,2,2)

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Energy Properties

Formation Energy/atom

-1.84004

eV/atom

Energy/atom

-6.42155

eV/atom

Energy above Hull

0.3501

eV/atom

Uncorrected Energy

-5.4652

eV/atom

Volume/atom

12.79

Å³

c/a Ratio

3.0225

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

5.0004

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.030070

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

4.0267

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

53.421%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

1.0064

smaller = more stable mixing

VEC

5.000

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-1.562

kJ/mol; negative = exothermic mixing

Entropy Norm

0.8346

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (3)

aaachray aaadtzyo aaadxuxf

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-1048483

Reference Citation

The crystal structure and related material properties of Ba2AlNi3O7 were obtained from the Materials Project database (MP-ID: mp-1048483, 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_Ba2AlNi3O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.75011200
_cell_length_b   3.91150900
_cell_length_c   11.33482500
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   90.00000000
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ba2AlNi3O7
_chemical_formula_sum   'Ba2 Al1 Ni3 O7'
_cell_volume   166.26597817
_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  0.31178500  1.0
  Ba  Ba1  1  0.50000000  0.50000000  0.68821500  1.0
  Al  Al2  1  0.50000000  0.50000000  0.00000000  1.0
  Ni  Ni3  1  0.00000000  0.00000000  0.14712300  1.0
  Ni  Ni4  1  0.00000000  0.00000000  0.85287700  1.0
  Ni  Ni5  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  0.11023600  1.0
  O  O8  1  0.50000000  0.00000000  0.88976400  1.0
  O  O9  1  0.00000000  0.50000000  0.10965900  1.0
  O  O10  1  0.00000000  0.50000000  0.89034100  1.0
  O  O11  1  0.00000000  0.00000000  0.33296200  1.0
  O  O12  1  0.00000000  0.00000000  0.66703800  1.0

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