BaAl5Ir2

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-3202845 · Space group: Immm (#71)

Materials Project API

Basic Information

Formula

BaAl5Ir2

MP-ID

mp-3202845

Elements

Sites

Density

6.5080

g/cm³

Volume

167.55

Å³

Cell a

6.8746

Cell b

6.8746

Cell c

6.8746

α Angle

144.00

β Angle

116.38

γ Angle

75.32

Space Group

Immm

Point Group

mmm

Crystal System

Orthorhombic

Bravais Lattice

Stability

Yes

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
16.29	5.4423	39.4	(1,1,-1)
22.47	3.9575	22.2	(1,0,-1)
24.29	3.6650	24.4	(0,0,1)
24.57	3.6235	47.4	(1,-1,1)
27.49	3.2443	48.7	(2,1,-1)
29.38	3.0399	100.0	(1,1,-2)
29.62	3.0161	4.6	(2,0,0)
32.92	2.7211	16.5	(2,2,-2)
33.53	2.6725	30.4	(1,0,1)
41.12	2.1951	3.8	(2,1,0)
41.12	2.1951	1.3	(0,3,-2)
41.32	2.1848	4.3	(3,1,-2)
41.50	2.1759	18.3	(3,1,-1)
42.56	2.1241	22.0	(1,-1,-1)
43.08	2.0999	14.4	(1,-1,2)
43.40	2.0849	7.5	(3,2,-2)
45.09	2.0108	5.4	(3,0,0)
45.86	1.9788	5.7	(2,0,-2)
46.34	1.9591	33.0	(2,0,1)
46.34	1.9591	11.0	(1,-3,2)
46.90	1.9374	13.0	(3,2,-3)
49.76	1.8325	14.4	(0,0,2)
50.37	1.8118	9.4	(2,-2,2)
51.42	1.7771	13.1	(2,1,-3)

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Energy Properties

Formation Energy/atom

-0.75045

eV/atom

Energy/atom

-21.36030

eV/atom

Energy above Hull

0.0000

eV/atom

Uncorrected Energy

-21.3603

eV/atom

Volume/atom

20.94

Å³

c/a Ratio

1.0000

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Total Mag. Moment

0.0001

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.000000

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

Al · 0.625

Element Family

PostTransition-Noble

Solute Fraction

0.375

Interstitial Fraction

0.000

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

0.9003

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

7.4847

J/mol·K

Ω Parameter

1.0684

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

16.407%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.3854

smaller = more stable mixing

VEC

4.375

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-9.760

kJ/mol; negative = exothermic mixing

Entropy Norm

0.8194

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.738

Family

Al-based Alloy

Matrix Element

Al · 0.625

Related Tasks

Related computation task IDs (1)

aaahafyj

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-3202845

Reference Citation

The crystal structure and related material properties of BaAl5Ir2 were obtained from the Materials Project database (MP-ID: mp-3202845, 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_BaAl5Ir2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.87458610
_cell_length_b   6.87458548
_cell_length_c   6.87458580
_cell_angle_alpha   144.00408576
_cell_angle_beta   116.38234658
_cell_angle_gamma   75.32012897
_symmetry_Int_Tables_number   1
_chemical_formula_structural   BaAl5Ir2
_chemical_formula_sum   'Ba1 Al5 Ir2'
_cell_volume   167.55190245
_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  0.00000000  0.00000000  0.00000000  1.0
  Al  Al1  1  0.50193755  0.31465682  0.18728073  1.0
  Al  Al2  1  0.87262491  0.68534318  0.18728073  1.0
  Al  Al3  1  0.50000100  0.00000000  0.50000100  1.0
  Al  Al4  1  0.12737609  0.31465682  0.81271927  1.0
  Al  Al5  1  0.49806245  0.68534218  0.81271927  1.0
  Ir  Ir6  1  0.71466088  0.21465988  0.50000100  1.0
  Ir  Ir7  1  0.28533912  0.78533912  0.49999900  1.0

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