AcNi2BIr

High-Entropy Materials HEA

MP-ID: mp-3248363 · Space group: Imma (#74)

Materials Project API

Basic Information

Formula

AcNi2BIr

MP-ID

mp-3248363

Elements

Sites

Density

11.3284

g/cm³

Volume

160.48

Å³

Cell a

6.2240

Cell b

6.2240

Cell c

6.2240

α Angle

132.94

β Angle

105.55

γ Angle

92.91

Space Group

Imma

Point Group

mmm

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
20.71	4.2880	16.9	(1,1,-1)
29.97	2.9813	26.8	(1,1,-2)
31.58	2.8327	100.0	(2,-1,0)
33.53	2.6726	22.7	(1,2,-2)
36.15	2.4850	9.9	(1,-1,-1)
36.25	2.4780	4.8	(2,1,-2)
37.33	2.4091	5.5	(1,-2,2)
37.33	2.4091	5.5	(2,-1,1)
39.61	2.2753	9.3	(1,0,-2)
42.02	2.1501	16.3	(2,0,-2)
42.02	2.1501	16.3	(0,2,0)
42.15	2.1440	5.0	(2,2,-2)
43.73	2.0699	15.9	(1,2,-3)
45.69	1.9858	8.5	(0,2,-3)
47.75	1.9046	10.0	(2,2,-3)
48.35	1.8826	6.8	(2,-2,2)
48.77	1.8671	2.3	(1,1,1)
48.89	1.8631	10.7	(1,3,-3)
50.13	1.8199	4.4	(2,1,-3)
53.13	1.7238	12.0	(1,-3,3)
56.78	1.6214	7.5	(3,2,-3)
59.69	1.5491	5.2	(1,3,-4)
61.23	1.5138	3.6	(2,0,-3)
61.74	1.5024	11.9	(1,2,-4)

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Energy Properties

Formation Energy/atom

-0.53482

eV/atom

Energy/atom

-30.99614

eV/atom

Energy above Hull

0.0000

eV/atom

Uncorrected Energy

-30.9961

eV/atom

Volume/atom

16.05

Å³

c/a Ratio

1.0000

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

Ni · 0.400

Element Family

3d-TM

Solute Fraction

0.600

Interstitial Fraction

0.200

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

1.3322

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

11.0757

J/mol·K

Ω Parameter

0.9527

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

25.588%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.3812

smaller = more stable mixing

VEC

6.800

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-22.942

kJ/mol; negative = exothermic mixing

Entropy Norm

0.9610

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (1)

aaahcvhb

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-3248363

Reference Citation

The crystal structure and related material properties of AcNi2BIr were obtained from the Materials Project database (MP-ID: mp-3248363, 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_AcNi2BIr
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.22403140
_cell_length_b   6.22403135
_cell_length_c   6.22403169
_cell_angle_alpha   132.93609028
_cell_angle_beta   105.55036235
_cell_angle_gamma   92.90800850
_symmetry_Int_Tables_number   1
_chemical_formula_structural   AcNi2BIr
_chemical_formula_sum   'Ac2 Ni4 B2 Ir2'
_cell_volume   160.48194651
_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
  Ac  Ac0  1  0.82345802  0.57345802  0.25000000  1.0
  Ac  Ac1  1  0.17654198  0.42654198  0.75000000  1.0
  Ni  Ni2  1  0.33260262  0.50000000  0.33260262  1.0
  Ni  Ni3  1  0.66739738  0.50000000  0.66739738  1.0
  Ni  Ni4  1  0.66739738  0.00000000  0.16739738  1.0
  Ni  Ni5  1  0.33260262  1.00000000  0.83260262  1.0
  B  B6  1  0.38403401  0.13403401  0.25000000  1.0
  B  B7  1  0.61596599  0.86596599  0.75000000  1.0
  Ir  Ir8  1  0.00000000  0.00000000  0.00000000  1.0
  Ir  Ir9  1  0.50000000  0.00000000  0.50000000  1.0

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