HoNi4B

High-Entropy Materials HEA Traditional Materials TRA Elasticity Data ELA

MP-ID: mp-10398 · Space group: P6/mmm (#191)

Materials Project API

Basic Information

Formula

HoNi4B

MP-ID

mp-10398

Elements

Sites

Density

9.4632

g/cm³

Volume

144.07

Å³

Cell a

4.9185

Cell b

4.9185

Cell c

6.8766

α Angle

90.00

β Angle

90.00

γ Angle

120.00

Space Group

P6/mmm

Point Group

6/mmm

Crystal System

Hexagonal

Bravais Lattice

Stability

Yes

Packing Fraction

0.7405

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
20.85	4.2596	15.0	(1,0,-1,0)
25.91	3.4383	3.8	(0,0,0,2)
33.49	2.6754	91.8	(1,0,-1,2)
36.54	2.4593	31.7	(2,-1,-1,0)
38.89	2.3156	10.1	(2,-1,-1,1)
39.31	2.2922	11.3	(0,0,0,3)
42.44	2.1298	73.9	(2,0,-2,0)
44.54	2.0344	7.7	(2,0,-2,1)
44.91	2.0185	6.7	(1,0,-1,3)
45.34	2.0003	100.0	(2,-1,-1,2)
50.40	1.8106	1.2	(2,0,-2,2)
53.29	1.7191	13.3	(0,0,0,4)
57.22	1.6100	2.6	(3,-1,-2,0)
57.84	1.5942	5.4	(1,0,-1,4)
59.22	1.5602	5.8	(2,0,-2,3)
63.84	1.4580	28.6	(3,-1,-2,2)
65.77	1.4199	5.6	(3,0,-3,0)
66.34	1.4090	15.3	(2,-1,-1,4)
67.34	1.3905	1.8	(3,0,-3,1)
70.38	1.3377	15.8	(2,0,-2,4)
71.63	1.3175	3.0	(3,-1,-2,3)
71.95	1.3124	24.1	(3,0,-3,2)
77.65	1.2296	20.6	(4,-2,-2,0)
79.92	1.2004	2.8	(2,-1,-1,5)

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Energy Properties

Formation Energy/atom

-0.49916

eV/atom

Energy/atom

-6.23210

eV/atom

Energy above Hull

0.0000

eV/atom

Uncorrected Energy

-15.1824

eV/atom

Volume/atom

12.01

Å³

c/a Ratio

1.3981

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

0.0000

μB

Mag. Ordering

Unknown

Mag. Sites

Magnetization/Volume

0.000000

μB/Å³

Elastic Properties

K_VRH

150.211

GPa

G_VRH

79.360

GPa

Young's Modulus E

202.430

GPa

Poisson Ratio ν

0.275

Pugh Ratio K/G

1.893

Vickers Hardness Est.

9.249

GPa

Ductility

Brittle

Anisotropy

0.162

Lame λ

97.304

GPa

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

Ni · 0.667

Element Family

3d-TM

Solute Fraction

0.333

Interstitial Fraction

0.167

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

0.8676

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

7.2129

J/mol·K

Ω Parameter

0.5948

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

19.602%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.2674

smaller = more stable mixing

VEC

9.000

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-22.222

kJ/mol; negative = exothermic mixing

Entropy Norm

0.7897

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.751

Family

Ni-based Alloy

Matrix Element

Ni · 0.667

Elasticity Features

Elastic Modulus Comparison (GPa)

Elastic Features

Elastic Anisotropy A^U

0.1620

Homogeneous Poisson ν

0.2750

Debye Temperature

497.5

Sound Velocity

3,224.8

m/s

Homogeneity

0.2750

Related Tasks

Related computation task IDs (5)

aaadmzpn aaadrkck aaaekqxo aaaetpfk aaafinkc

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-10398

Reference Citation

The crystal structure and related material properties of HoNi4B were obtained from the Materials Project database (MP-ID: mp-10398, 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_HoNi4B
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.91850163
_cell_length_b   4.91850157
_cell_length_c   6.87656807
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   120.00000036
_symmetry_Int_Tables_number   1
_chemical_formula_structural   HoNi4B
_chemical_formula_sum   'Ho2 Ni8 B2'
_cell_volume   144.06816023
_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
  Ho  Ho0  1  -0.00000000  0.00000000  0.50000000  1.0
  Ho  Ho1  1  -0.00000000  0.00000000  0.00000000  1.0
  Ni  Ni2  1  -0.00000000  0.50000000  0.20860201  1.0
  Ni  Ni3  1  0.50000000  0.00000000  0.79139799  1.0
  Ni  Ni4  1  0.50000000  0.50000000  0.79139799  1.0
  Ni  Ni5  1  -0.00000000  0.50000000  0.79139799  1.0
  Ni  Ni6  1  0.33333300  0.66666700  0.50000000  1.0
  Ni  Ni7  1  0.66666700  0.33333300  0.50000000  1.0
  Ni  Ni8  1  0.50000000  0.00000000  0.20860201  1.0
  Ni  Ni9  1  0.50000000  0.50000000  0.20860201  1.0
  B  B10  1  0.33333300  0.66666700  0.00000000  1.0
  B  B11  1  0.66666700  0.33333300  0.00000000  1.0

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