Hf4Ta2Al7

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-3203045 · Space group: R-3m (#166)

Materials Project API

Basic Information

Formula

Hf4Ta2Al7

MP-ID

mp-3203045

Elements

Sites

Density

9.3070

g/cm³

Volume

225.65

Å³

Cell a

10.0330

Cell b

10.0330

Cell c

10.0330

α Angle

30.14

β Angle

30.14

γ Angle

30.14

Space Group

R-3m

Point Group

-3m

Crystal System

Trigonal

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
9.24	9.5700	43.8	(1,1,1)
18.54	4.7850	45.6	(2,2,2)
19.89	4.4639	17.2	(1,0,0)
19.89	4.4639	34.5	(0,1,0)
23.26	3.8241	17.6	(2,1,1)
23.26	3.8241	8.8	(1,2,1)
25.08	3.5511	1.9	(2,2,1)
31.84	2.8103	2.5	(2,3,3)
31.84	2.8103	5.0	(3,3,2)
34.37	2.6090	53.2	(1,0,-1)
34.37	2.6090	53.2	(1,-1,0)
34.37	2.6090	53.2	(0,1,-1)
35.67	2.5171	7.7	(2,1,0)
35.67	2.5171	7.7	(2,0,1)
37.10	2.4233	100.0	(4,3,3)
37.59	2.3925	2.3	(4,4,4)
39.33	2.2906	30.6	(3,2,1)
39.33	2.2906	61.3	(3,1,2)
39.89	2.2601	44.3	(4,4,3)
39.89	2.2601	22.1	(4,3,4)
40.03	2.2525	7.7	(1,-1,-1)
40.03	2.2525	15.4	(1,1,-1)
40.41	2.2319	1.0	(2,0,0)
41.92	2.1552	4.6	(0,2,2)

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Energy Properties

Formation Energy/atom

-0.47985

eV/atom

Energy/atom

-25.47324

eV/atom

Energy above Hull

0.0000

eV/atom

Uncorrected Energy

-25.4732

eV/atom

Volume/atom

17.36

Å³

c/a Ratio

1.0000

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Total Mag. Moment

0.0021

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 · 0.538

Element Family

PostTransition-Noble

Solute Fraction

0.462

Interstitial Fraction

0.000

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

0.9840

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

8.1807

J/mol·K

Ω Parameter

0.4439

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

4.820%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.1372

smaller = more stable mixing

VEC

3.615

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-32.805

kJ/mol; negative = exothermic mixing

Entropy Norm

0.8956

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.706

Family

Al-based Alloy

Matrix Element

Al · 0.538

Related Tasks

Related computation task IDs (1)

aaahaggb

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-3203045

Reference Citation

The crystal structure and related material properties of Hf4Ta2Al7 were obtained from the Materials Project database (MP-ID: mp-3203045, 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_Hf4Ta2Al7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.03296694
_cell_length_b   10.03296690
_cell_length_c   10.03296727
_cell_angle_alpha   30.14462949
_cell_angle_beta   30.14464143
_cell_angle_gamma   30.14463598
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Hf4Ta2Al7
_chemical_formula_sum   'Hf4 Ta2 Al7'
_cell_volume   225.64985015
_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
  Hf  Hf0  1  0.83473706  0.83473706  0.83473706  1.0
  Hf  Hf1  1  0.16526294  0.16526294  0.16526294  1.0
  Hf  Hf2  1  0.64859385  0.64859385  0.64859385  1.0
  Hf  Hf3  1  0.35140615  0.35140615  0.35140615  1.0
  Ta  Ta4  1  0.54450301  0.54450301  0.54450301  1.0
  Ta  Ta5  1  0.45549699  0.45549699  0.45549699  1.0
  Al  Al6  1  0.00000000  0.00000000  0.00000000  1.0
  Al  Al7  1  0.90831397  0.41406339  0.90831397  1.0
  Al  Al8  1  0.90831397  0.90831397  0.41406339  1.0
  Al  Al9  1  0.41406339  0.90831397  0.90831397  1.0
  Al  Al10  1  0.09168603  0.58593661  0.09168603  1.0
  Al  Al11  1  0.09168603  0.09168603  0.58593661  1.0
  Al  Al12  1  0.58593661  0.09168603  0.09168603  1.0

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