Ho2AlNi2

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-1069801 · Space group: Immm (#71)

Materials Project API

Basic Information

Formula

Ho2AlNi2

MP-ID

mp-1069801

Elements

Sites

Density

8.6589

g/cm³

Volume

90.94

Å³

Cell a

5.3168

Cell b

5.3168

Cell c

5.3168

α Angle

134.05

β Angle

119.71

γ Angle

79.00

Space Group

Immm

Point Group

mmm

Crystal System

Orthorhombic

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
19.84	4.4758	14.0	(0,1,-1)
21.66	4.1026	10.2	(1,1,-1)
27.21	3.2773	80.5	(1,-1,0)
33.56	2.6701	14.6	(1,-1,1)
35.04	2.5606	100.0	(2,0,-1)
36.92	2.4344	31.8	(1,2,-2)
39.46	2.2839	47.5	(2,1,-2)
40.30	2.2379	48.3	(0,2,-2)
41.70	2.1660	39.6	(1,-2,1)
43.61	2.0755	32.7	(1,-1,-1)
44.15	2.0513	10.5	(2,2,-2)
48.34	1.8829	2.8	(2,-1,-1)
49.20	1.8520	2.7	(2,0,-2)
52.64	1.7388	2.2	(2,2,-3)
52.74	1.7356	3.5	(0,3,-2)
56.13	1.6387	7.1	(2,-2,0)
56.23	1.6360	15.4	(2,-2,1)
58.43	1.5794	16.9	(3,0,-2)
58.87	1.5687	11.3	(2,3,-3)
60.68	1.5261	5.5	(3,2,-3)
60.87	1.5218	28.1	(3,-1,-1)
60.97	1.5196	13.9	(1,-3,2)
62.23	1.4919	10.0	(0,3,-3)
63.79	1.4590	6.7	(3,1,-3)

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Energy Properties

Formation Energy/atom

-0.55070

eV/atom

Energy/atom

-5.45094

eV/atom

Energy above Hull

0.0003

eV/atom

Uncorrected Energy

-19.8556

eV/atom

Volume/atom

18.19

Å³

c/a Ratio

1.0000

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

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

Ho · 0.400

Element Family

Lanthanide

Solute Fraction

0.600

Interstitial Fraction

0.000

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

1.0549

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

8.7706

J/mol·K

Ω Parameter

1.9578

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

15.490%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.3045

smaller = more stable mixing

VEC

9.000

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-7.040

kJ/mol; negative = exothermic mixing

Entropy Norm

0.9602

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.468

Family

Ho-rich Multi-Component

Matrix Element

Ho · 0.400

Related Tasks

Related computation task IDs (5)

aaaciwvu aaadsonl aaaekvft aaaeuqvt aaafsrab

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-1069801

Reference Citation

The crystal structure and related material properties of Ho2AlNi2 were obtained from the Materials Project database (MP-ID: mp-1069801, 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_Ho2AlNi2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.31683482
_cell_length_b   5.31683482
_cell_length_c   5.31683482
_cell_angle_alpha   134.04553611
_cell_angle_beta   119.70928203
_cell_angle_gamma   78.99881883
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ho2AlNi2
_chemical_formula_sum   'Ho2 Al1 Ni2'
_cell_volume   90.94383510
_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  0.70275750  0.20275750  0.50000000  1.0
  Ho  Ho1  1  0.29724250  0.79724250  0.50000000  1.0
  Al  Al2  1  -0.00000000  -0.00000000  -0.00000000  1.0
  Ni  Ni3  1  0.26695159  0.50000000  0.76695159  1.0
  Ni  Ni4  1  0.73304841  0.50000000  0.23304841  1.0

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