Ta9NbAl5

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-3292916 · Space group: Cmm2 (#35)

Materials Project API

Basic Information

Formula

Ta9NbAl5

MP-ID

mp-3292916

Elements

Sites

Density

12.0783

g/cm³

Volume

510.43

Å³

Cell a

9.9292

Cell b

9.9292

Cell c

5.1773

α Angle

90.00

β Angle

90.00

γ Angle

90.02

Space Group

Cmm2

Point Group

mm2

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
8.91	9.9292	2.7	(1,0,0)
12.61	7.0222	20.0	(1,-1,0)
12.61	7.0197	1.5	(1,1,0)
17.13	5.1773	2.0	(0,0,1)
19.33	4.5907	86.3	(1,0,1)
19.99	4.4411	13.0	(2,-1,0)
20.00	4.4398	7.7	(2,1,0)
21.32	4.1672	14.7	(1,-1,1)
21.32	4.1667	13.3	(1,1,1)
24.85	3.5833	1.3	(2,0,1)
25.37	3.5111	3.7	(2,-2,0)
25.38	3.5099	8.0	(2,2,0)
26.44	3.3708	8.1	(2,-1,1)
26.45	3.3703	9.6	(2,1,1)
26.94	3.3097	1.0	(3,0,0)
28.42	3.1402	8.8	(3,-1,0)
28.43	3.1396	11.7	(3,1,0)
30.77	2.9059	1.1	(2,-2,1)
32.10	2.7886	34.2	(3,0,1)
32.51	2.7543	14.0	(3,-2,0)
32.52	2.7534	6.7	(3,2,0)
33.37	2.6849	34.2	(3,-1,1)
33.38	2.6845	33.0	(3,1,1)
34.65	2.5887	16.9	(0,0,2)

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Energy Properties

Formation Energy/atom

-0.30135

eV/atom

Energy/atom

-33.34942

eV/atom

Energy above Hull

0.0000

eV/atom

Uncorrected Energy

-33.3494

eV/atom

Volume/atom

17.01

Å³

c/a Ratio

0.5214

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Total Mag. Moment

0.0004

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

Ta · 0.600

Element Family

5d-TM

Solute Fraction

0.400

Interstitial Fraction

0.000

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

0.8532

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

7.0938

J/mol·K

Ω Parameter

1.0423

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

0.975%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.0531

smaller = more stable mixing

VEC

4.333

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-16.800

kJ/mol; negative = exothermic mixing

Entropy Norm

0.7766

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.607

Family

Ta-rich Multi-Component

Matrix Element

Ta · 0.600

Related Tasks

Related computation task IDs (1)

aaahfjeq

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-3292916

Reference Citation

The crystal structure and related material properties of Ta9NbAl5 were obtained from the Materials Project database (MP-ID: mp-3292916, 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…

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Raw CIF Data

# generated using pymatgen
data_Ta9NbAl5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.92917814
_cell_length_b   9.92917814
_cell_length_c   5.17732866
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   90.02033824
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ta9NbAl5
_chemical_formula_sum   'Ta18 Nb2 Al10'
_cell_volume   510.42544169
_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
  Ta  Ta0  1  0.39831143  0.39831143  0.99999174  1.0
  Ta  Ta1  1  0.89725555  0.10274445  0.49891465  1.0
  Ta  Ta2  1  0.10274445  0.89725555  0.49891465  1.0
  Ta  Ta3  1  0.60168857  0.60168857  0.99999174  1.0
  Ta  Ta4  1  0.12887410  0.46511555  0.00058598  1.0
  Ta  Ta5  1  0.96399228  0.37132672  0.49965625  1.0
  Ta  Ta6  1  0.03600772  0.62867328  0.49965625  1.0
  Ta  Ta7  1  0.87112590  0.53488445  0.00058598  1.0
  Ta  Ta8  1  0.37132672  0.96399228  0.49965625  1.0
  Ta  Ta9  1  0.62867328  0.03600772  0.49965625  1.0
  Ta  Ta10  1  0.46511555  0.12887410  0.00058598  1.0
  Ta  Ta11  1  0.53488445  0.87112590  0.00058598  1.0
  Ta  Ta12  1  0.18195188  0.18195188  0.25210525  1.0
  Ta  Ta13  1  0.68159768  0.31840232  0.75167076  1.0
  Ta  Ta14  1  0.31840232  0.68159768  0.75167076  1.0
  Ta  Ta15  1  0.81804812  0.81804812  0.25210525  1.0
  Ta  Ta16  1  0.31810679  0.68189321  0.24835310  1.0
  Ta  Ta17  1  0.68189321  0.31810679  0.24835310  1.0
  Nb  Nb18  1  0.18159599  0.18159599  0.74778504  1.0
  Nb  Nb19  1  0.81840401  0.81840401  0.74778504  1.0
  Al  Al20  1  0.00000000  0.00000000  0.00004055  1.0
  Al  Al21  1  0.50000000  0.50000000  0.49988195  1.0
  Al  Al22  1  0.26218245  0.93340242  0.00006457  1.0
  Al  Al23  1  0.43371291  0.23784156  0.50030355  1.0
  Al  Al24  1  0.56628709  0.76215844  0.50030355  1.0
  Al  Al25  1  0.73781755  0.06659758  0.00006457  1.0
  Al  Al26  1  0.23784156  0.43371291  0.50030355  1.0
  Al  Al27  1  0.76215844  0.56628709  0.50030355  1.0
  Al  Al28  1  0.93340242  0.26218245  0.00006457  1.0
  Al  Al29  1  0.06659758  0.73781755  0.00006457  1.0

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