Tb2Al9Ir2Au

High-Entropy Materials HEA

MP-ID: mp-3294874 · Space group: Cmcm (#63)

Materials Project API

Basic Information

Formula

Tb2Al9Ir2Au

MP-ID

mp-3294874

Elements

Sites

Density

8.0664

g/cm³

Volume

470.22

Å³

Cell a

7.5849

Cell b

7.5849

Cell c

9.3919

α Angle

90.00

β Angle

90.00

γ Angle

119.51

Space Group

Cmcm

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
13.41	6.6008	7.5	(1,0,-1,0)
13.51	6.5525	8.7	(1,-1,0,0)
16.41	5.4004	19.0	(1,0,-1,1)
18.90	4.6959	26.2	(0,0,0,2)
23.25	3.8264	2.3	(1,0,-1,2)
23.28	3.8204	28.5	(1,1,-2,0)
23.30	3.8170	3.1	(1,-1,0,2)
23.46	3.7923	54.3	(2,-1,-1,0)
25.17	3.5388	17.3	(1,1,-2,1)
25.33	3.5165	32.4	(2,-1,-1,1)
27.22	3.2763	3.5	(2,-2,0,0)
28.67	3.1137	4.2	(2,0,-2,1)
28.67	3.1137	4.2	(0,2,-2,1)
30.16	2.9635	86.2	(1,1,-2,2)
30.29	2.9504	87.2	(2,-1,-1,2)
30.29	2.9504	87.2	(1,-2,1,2)
31.63	2.8286	5.0	(1,0,-1,3)
33.18	2.7002	1.9	(2,0,-2,2)
33.35	2.6870	14.2	(2,-2,0,2)
35.92	2.5001	4.9	(2,1,-3,0)
36.12	2.4870	1.6	(3,-1,-2,0)
37.13	2.4215	21.3	(1,1,-2,3)
37.24	2.4143	42.0	(2,-1,-1,3)
37.41	2.4041	6.7	(3,-1,-2,1)

Get direct link

Energy Properties

Formation Energy/atom

-0.85653

eV/atom

Energy/atom

-20.73835

eV/atom

Energy above Hull

0.0000

eV/atom

Uncorrected Energy

-20.7384

eV/atom

Volume/atom

16.79

Å³

c/a Ratio

1.2382

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Total Mag. Moment

0.0028

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.000010

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

Al · 0.643

Element Family

PostTransition-Noble

Solute Fraction

0.357

Interstitial Fraction

0.000

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

1.0285

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

8.5511

J/mol·K

Ω Parameter

0.9482

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

8.071%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.3776

smaller = more stable mixing

VEC

5.286

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-11.900

kJ/mol; negative = exothermic mixing

Entropy Norm

0.7419

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (1)

aaahfmby

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-3294874

Reference Citation

The crystal structure and related material properties of Tb2Al9Ir2Au were obtained from the Materials Project database (MP-ID: mp-3294874, 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…

Style: Ball & Stick | Drag to rotate · Scroll to zoom · Right-click to pan

Raw CIF Data

# generated using pymatgen
data_Tb2Al9Ir2Au
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.58492088
_cell_length_b   7.58492023
_cell_length_c   9.39187341
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   119.51245899
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Tb2Al9Ir2Au
_chemical_formula_sum   'Tb4 Al18 Ir4 Au2'
_cell_volume   470.21625166
_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
  Tb  Tb0  1  0.99541668  0.67593120  0.25000000  1.0
  Tb  Tb1  1  0.00458332  0.32406880  0.75000000  1.0
  Tb  Tb2  1  0.67593120  0.99541668  0.25000000  1.0
  Tb  Tb3  1  0.32406880  0.00458332  0.75000000  1.0
  Al  Al4  1  0.14144679  0.14144679  0.25000000  1.0
  Al  Al5  1  0.85855321  0.85855321  0.75000000  1.0
  Al  Al6  1  0.00161544  0.34464731  0.07598350  1.0
  Al  Al7  1  0.99838456  0.65535269  0.92401650  1.0
  Al  Al8  1  0.99838456  0.65535269  0.57598350  1.0
  Al  Al9  1  0.34464731  0.00161544  0.42401650  1.0
  Al  Al10  1  0.00161544  0.34464731  0.42401650  1.0
  Al  Al11  1  0.65535269  0.99838456  0.57598350  1.0
  Al  Al12  1  0.65535269  0.99838456  0.92401650  1.0
  Al  Al13  1  0.34464731  0.00161544  0.07598350  1.0
  Al  Al14  1  0.34181819  0.34181819  0.55591552  1.0
  Al  Al15  1  0.65818181  0.65818181  0.44408448  1.0
  Al  Al16  1  0.65818181  0.65818181  0.05591552  1.0
  Al  Al17  1  0.34181819  0.34181819  0.94408448  1.0
  Al  Al18  1  0.33835680  0.55125878  0.25000000  1.0
  Al  Al19  1  0.66164320  0.44874122  0.75000000  1.0
  Al  Al20  1  0.55125878  0.33835680  0.25000000  1.0
  Al  Al21  1  0.44874122  0.66164320  0.75000000  1.0
  Ir  Ir22  1  0.67182260  0.32817740  0.00000000  1.0
  Ir  Ir23  1  0.32817740  0.67182260  0.00000000  1.0
  Ir  Ir24  1  0.32817740  0.67182260  0.50000000  1.0
  Ir  Ir25  1  0.67182260  0.32817740  0.50000000  1.0
  Au  Au26  1  0.00000000  0.00000000  0.00000000  1.0
  Au  Au27  1  0.00000000  0.00000000  0.50000000  1.0

Get direct link