Ho2B4Ir4Os

High-Entropy Materials HEA

MP-ID: mp-3249944 · Space group: F222 (#22)

Materials Project API

Basic Information

Formula

Ho2B4Ir4Os

MP-ID

mp-3249944

Elements

Sites

Density

14.6319

g/cm³

Volume

151.19

Å³

Cell a

7.4774

Cell b

6.3590

Cell c

5.5289

α Angle

77.60

β Angle

56.16

γ Angle

46.23

Space Group

F222

Point Group

222

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
15.45	5.7349	4.8	(1,1,0)
18.49	4.7981	12.0	(1,0,1)
24.18	3.6800	3.5	(2,1,1)
29.96	2.9828	12.1	(2,1,0)
29.96	2.9828	36.3	(1,1,-1)
31.19	2.8675	19.0	(2,2,0)
32.59	2.7472	2.0	(0,1,1)
36.50	2.4614	51.1	(3,2,1)
37.49	2.3990	50.1	(2,0,2)
37.73	2.3841	100.0	(1,1,2)
40.26	2.2402	25.9	(3,1,1)
41.00	2.2014	1.4	(2,0,0)
43.79	2.0672	5.4	(3,2,0)
43.79	2.0672	1.8	(2,3,0)
45.74	1.9837	14.9	(2,1,-1)
45.74	1.9837	14.9	(2,3,1)
47.57	1.9117	2.2	(3,3,0)
49.54	1.8400	6.3	(4,2,2)
49.54	1.8400	6.3	(0,2,-2)
49.74	1.8332	18.3	(1,1,-2)
49.74	1.8332	6.1	(1,3,0)
51.46	1.7759	3.1	(4,3,1)
51.79	1.7653	3.8	(4,2,1)
51.79	1.7653	1.3	(1,3,-1)

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Energy Properties

Formation Energy/atom

-0.79957

eV/atom

Energy/atom

-33.30600

eV/atom

Energy above Hull

0.0000

eV/atom

Uncorrected Energy

-33.3060

eV/atom

Volume/atom

13.74

Å³

c/a Ratio

0.7394

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Total Mag. Moment

0.0000

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

B · 0.364

Element Family

Metalloid-Nonmetal

Solute Fraction

0.636

Interstitial Fraction

0.364

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

1.2637

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

10.5060

J/mol·K

Ω Parameter

2.6419

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

24.428%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.3541

smaller = more stable mixing

VEC

7.091

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-9.807

kJ/mol; negative = exothermic mixing

Entropy Norm

0.9115

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (1)

aaahcxpw

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-3249944

Reference Citation

The crystal structure and related material properties of Ho2B4Ir4Os were obtained from the Materials Project database (MP-ID: mp-3249944, 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_Ho2B4Ir4Os
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.47735901
_cell_length_b   6.35899130
_cell_length_c   5.52888580
_cell_angle_alpha   77.60411300
_cell_angle_beta   56.16117650
_cell_angle_gamma   46.23470851
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ho2B4Ir4Os
_chemical_formula_sum   'Ho2 B4 Ir4 Os1'
_cell_volume   151.18825576
_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  0.63872325  0.63872425  0.36127675  1.0
  Ho  Ho1  1  0.36127575  0.36127675  0.63872425  1.0
  B  B2  1  0.28410780  0.98314760  0.02939023  1.0
  B  B3  1  0.02938923  0.70335537  0.28410880  1.0
  B  B4  1  0.98314660  0.28410880  0.70335537  1.0
  B  B5  1  0.70335437  0.02939023  0.98314660  1.0
  Ir  Ir6  1  0.00000000  0.00000000  0.00000000  1.0
  Ir  Ir7  1  0.50048705  0.50048505  0.99951395  1.0
  Ir  Ir8  1  0.99951395  0.99951395  0.50048605  1.0
  Ir  Ir9  1  0.75000100  0.74999900  0.75000000  1.0
  Os  Os10  1  0.25000100  0.24999900  0.25000000  1.0

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