Ho(Al2Fe)4

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-31179 · Space group: I4/mmm (#139)

Materials Project API

Basic Information

Formula

Ho(Al2Fe)4

MP-ID

mp-31179

Elements

Sites

Density

5.3255

g/cm³

Volume

188.38

Å³

Cell a

4.9840

Cell b

6.6324

Cell c

6.6324

α Angle

81.89

β Angle

67.97

γ Angle

67.97

Space Group

I4/mmm

Point Group

4/mmm

Crystal System

Tetragonal

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
14.41	6.1480	75.5	(0,0,1)
14.41	6.1480	75.5	(0,1,0)
20.42	4.3482	4.6	(0,1,1)
20.43	4.3464	4.6	(0,1,-1)
20.53	4.3259	35.0	(1,0,0)
20.54	4.3237	34.9	(1,0,1)
20.54	4.3237	34.9	(1,1,0)
20.55	4.3225	34.9	(1,1,1)
29.05	3.0740	65.5	(0,0,2)
29.05	3.0740	65.4	(0,2,0)
29.11	3.0672	23.2	(1,0,-1)
29.11	3.0672	23.2	(1,-1,0)
29.12	3.0661	23.2	(1,1,-1)
29.12	3.0661	23.2	(1,-1,1)
29.14	3.0649	23.2	(1,0,2)
29.14	3.0649	23.2	(1,2,0)
29.14	3.0648	23.2	(1,1,2)
29.14	3.0647	23.2	(1,2,1)
32.56	2.7499	21.4	(0,1,2)
32.56	2.7499	21.4	(0,2,1)
32.57	2.7490	21.4	(0,1,-2)
32.57	2.7490	21.4	(0,2,-1)
35.82	2.5068	34.6	(1,-1,-1)
35.85	2.5050	34.6	(1,-1,2)

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Energy Properties

Formation Energy/atom

-0.43021

eV/atom

Energy/atom

-5.69501

eV/atom

Energy above Hull

0.0000

eV/atom

Uncorrected Energy

-11.4950

eV/atom

Volume/atom

14.49

Å³

c/a Ratio

1.3307

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

6.8937

μB

Mag. Ordering

Unknown

Mag. Sites

Magnetization/Volume

0.036590

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

Al · 0.615

Element Family

PostTransition-Noble

Solute Fraction

0.385

Interstitial Fraction

0.000

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

0.8587

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

7.1396

J/mol·K

Ω Parameter

1.0841

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

9.021%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.1566

smaller = more stable mixing

VEC

5.154

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-8.331

kJ/mol; negative = exothermic mixing

Entropy Norm

0.7817

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.695

Family

Al-based Alloy

Matrix Element

Al · 0.615

Related Tasks

Related computation task IDs (5)

aaadncwd aaadrmmz aaaelqva aaaetxef aaafsdkv

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-31179

Reference Citation

The crystal structure and related material properties of Ho(Al2Fe)4 were obtained from the Materials Project database (MP-ID: mp-31179, 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_Ho(Al2Fe)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.98396564
_cell_length_b   6.63236169
_cell_length_c   6.63237006
_cell_angle_alpha   81.88926276
_cell_angle_beta   67.96729089
_cell_angle_gamma   67.96729418
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ho(Al2Fe)4
_chemical_formula_sum   'Ho1 Al8 Fe4'
_cell_volume   188.38363800
_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
  Ho  Ho0  1  0.00000000  -0.00000000  0.00000000  1.0
  Al  Al1  1  0.34118927  0.65863579  0.65862370  1.0
  Al  Al2  1  0.00000787  0.34142517  0.65856248  1.0
  Al  Al3  1  -0.00000787  0.65857483  0.34143752  1.0
  Al  Al4  1  0.65881073  0.34136421  0.34137630  1.0
  Al  Al5  1  0.27861367  0.22155239  0.22157189  1.0
  Al  Al6  1  0.49998847  0.77853558  0.22148373  1.0
  Al  Al7  1  0.50001153  0.22146442  0.77851627  1.0
  Al  Al8  1  0.72138633  0.77844761  0.77842811  1.0
  Fe  Fe9  1  0.50000000  -0.00000000  0.50000000  1.0
  Fe  Fe10  1  0.00000000  0.50000000  0.00000000  1.0
  Fe  Fe11  1  0.50000000  0.50000000  0.00000000  1.0
  Fe  Fe12  1  0.00000000  -0.00000000  0.50000000  1.0

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