Ho7FeI12

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-991234 · Space group: P-1 (#2)

Materials Project API

Basic Information

Formula

Ho7FeI12

MP-ID

mp-991234

Elements

Sites

Density

3.5376

g/cm³

Volume

1,282.97

Å³

Cell a

9.0480

Cell b

12.7958

Cell c

12.7958

α Angle

120.00

β Angle

90.00

γ Angle

90.00

Space Group

P-1

Point Group

-1

Crystal System

Triclinic

Bravais Lattice

Stability

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
7.98	11.0815	15.6	(0,0,0,1)
9.78	9.0480	2.5	(1,0,-1,0)
12.63	7.0086	7.7	(1,0,-1,1)
13.84	6.3979	100.0	(0,1,-1,-2)
16.00	5.5407	7.3	(0,0,0,2)
16.97	5.2239	8.5	(1,-1,0,2)
18.78	4.7252	7.0	(1,0,-1,2)
21.21	4.1884	6.8	(0,1,-1,-3)
23.40	3.8009	9.1	(1,-1,0,3)
24.09	3.6938	4.0	(0,0,0,3)
24.09	3.6938	2.2	(2,2,-4,-1)
25.42	3.5043	2.5	(2,0,-2,2)
26.06	3.4198	5.0	(1,0,-1,3)
27.89	3.1990	14.8	(0,2,-2,-4)
29.05	3.0735	10.9	(0,1,-1,-4)
29.62	3.0160	4.0	(1,2,-3,-4)
30.72	2.9101	32.0	(1,1,-2,-4)
31.26	2.8612	3.0	(2,0,-2,3)
33.84	2.6490	4.0	(1,0,-1,4)
35.30	2.5423	7.6	(0,2,-2,-5)
36.72	2.4475	19.7	(3,2,-5,1)
37.18	2.4182	1.7	(0,1,-1,-5)
38.09	2.3626	7.7	(2,0,-2,4)
38.54	2.3362	16.3	(1,-1,0,5)

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Energy Properties

Formation Energy/atom

0.11641

eV/atom

Energy/atom

-2.83069

eV/atom

Energy above Hull

1.5120

eV/atom

Uncorrected Energy

-2.6033

eV/atom

Volume/atom

64.15

Å³

c/a Ratio

1.4142

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

2.4585

μB

Mag. Ordering

FiM

Mag. Sites

Magnetization/Volume

0.001920

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

I · 0.600

Element Family

Metalloid-Nonmetal

Solute Fraction

0.400

Interstitial Fraction

0.000

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

0.8237

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

6.8484

J/mol·K

Ω Parameter

0.0000

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

11.527%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.6756

smaller = more stable mixing

VEC

7.250

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

0.000

kJ/mol; negative = exothermic mixing

Entropy Norm

0.7498

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.336

Family

I-rich Multi-Component

Matrix Element

I · 0.600

Related Tasks

Related computation task IDs (1)

aaacekik

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-991234

Reference Citation

The crystal structure and related material properties of Ho7FeI12 were obtained from the Materials Project database (MP-ID: mp-991234, 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_Ho7FeI12
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.04799700
_cell_length_b   12.79580000
_cell_length_c   12.79580012
_cell_angle_alpha   119.99999969
_cell_angle_beta   90.00000000
_cell_angle_gamma   90.00000000
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ho7FeI12
_chemical_formula_sum   'Ho7 Fe1 I12'
_cell_volume   1282.97434416
_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  0.21394200  0.47888800  0.93074700  1.0
  Ho  Ho1  1  0.59036400  0.78605800  0.73505400  1.0
  Ho  Ho2  1  0.52111200  0.59036400  0.19569400  1.0
  Ho  Ho3  1  0.40963600  0.21394200  0.26494600  1.0
  Ho  Ho4  1  0.00000000  0.00000000  0.00000000  1.0
  Ho  Ho5  1  0.47888800  0.40963600  0.80430600  1.0
  Ho  Ho6  1  0.78605800  0.52111200  0.06925300  1.0
  Fe  Fe7  1  0.50000000  0.50000000  0.00000000  1.0
  I  I8  1  0.33888100  0.03838200  0.07673200  1.0
  I  I9  1  0.27551800  0.82049800  0.60818300  1.0
  I  I10  1  0.11511300  0.33888100  0.69950100  1.0
  I  I11  1  0.72448200  0.17950200  0.39181700  1.0
  I  I12  1  0.82049800  0.42868100  0.84683700  1.0
  I  I13  1  0.96161800  0.88488700  0.77623300  1.0
  I  I14  1  0.42868100  0.27551800  0.54498000  1.0
  I  I15  1  0.88488700  0.66111900  0.30049900  1.0
  I  I16  1  0.17950200  0.57131900  0.15316300  1.0
  I  I17  1  0.57131900  0.72448200  0.45502000  1.0
  I  I18  1  0.03838200  0.11511300  0.22376700  1.0
  I  I19  1  0.66111900  0.96161800  0.92326800  1.0

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