NaAc(BIr)4

High-Entropy Materials HEA

MP-ID: mp-3246953 · Space group: F222 (#22)

Materials Project API

Basic Information

Formula

NaAc(BIr)4

MP-ID

mp-3246953

Elements

Sites

Density

11.6109

g/cm³

Volume

151.90

Å³

Cell a

7.1429

Cell b

6.1737

Cell c

5.5665

α Angle

74.75

β Angle

56.50

γ Angle

48.75

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
16.44	5.3921	8.9	(1,1,0)
18.94	4.6847	8.4	(1,0,1)
19.38	4.5813	52.2	(1,1,1)
25.18	3.5364	6.3	(2,1,1)
29.71	3.0066	2.8	(0,1,1)
30.50	2.9306	100.0	(2,2,1)
33.23	2.6961	12.2	(2,2,0)
33.38	2.6844	10.8	(2,1,2)
34.14	2.6260	2.6	(1,2,1)
34.14	2.6260	2.6	(1,0,-1)
35.48	2.5303	90.5	(1,1,2)
38.43	2.3424	37.1	(2,0,2)
38.53	2.3367	1.6	(3,2,1)
38.53	2.3367	1.6	(1,2,-1)
39.33	2.2907	4.3	(2,2,2)
41.12	2.1950	12.5	(3,2,2)
41.12	2.1950	37.4	(3,1,1)
42.06	2.1484	1.7	(3,1,2)
45.17	2.0072	2.0	(2,3,1)
45.73	1.9842	21.2	(3,3,1)
47.13	1.9285	5.2	(1,2,2)
49.32	1.8478	1.4	(2,1,3)
49.40	1.8450	10.0	(3,3,2)
49.40	1.8450	10.0	(3,1,0)

Get direct link

Energy Properties

Formation Energy/atom

-0.65736

eV/atom

Energy/atom

-31.75981

eV/atom

Energy above Hull

0.0000

eV/atom

Uncorrected Energy

-31.7598

eV/atom

Volume/atom

15.19

Å³

c/a Ratio

0.7793

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 · 0.400

Element Family

Metalloid-Nonmetal

Solute Fraction

0.600

Interstitial Fraction

0.400

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

1.1936

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

9.9232

J/mol·K

Ω Parameter

1.1282

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

28.996%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.4494

smaller = more stable mixing

VEC

5.100

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-19.390

kJ/mol; negative = exothermic mixing

Entropy Norm

0.8610

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (1)

aaahctev

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-3246953

Reference Citation

The crystal structure and related material properties of NaAc(BIr)4 were obtained from the Materials Project database (MP-ID: mp-3246953, 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…

Style: Ball & Stick | Drag to rotate · Scroll to zoom · Right-click to pan

Raw CIF Data

# generated using pymatgen
data_NaAc(BIr)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.14292632
_cell_length_b   6.17368763
_cell_length_c   5.56653291
_cell_angle_alpha   74.74945017
_cell_angle_beta   56.49847360
_cell_angle_gamma   48.75206724
_symmetry_Int_Tables_number   1
_chemical_formula_structural   NaAc(BIr)4
_chemical_formula_sum   'Na1 Ac1 B4 Ir4'
_cell_volume   151.89656781
_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
  Na  Na0  1  0.50000000  0.50000000  0.50000000  1.0
  Ac  Ac1  1  0.75000000  0.75000000  0.75000000  1.0
  B  B2  1  0.17684944  0.82315056  0.17684944  1.0
  B  B3  1  0.07797430  0.42202570  0.07797430  1.0
  B  B4  1  0.82315056  0.17684944  0.82315056  1.0
  B  B5  1  0.42202570  0.07797430  0.42202570  1.0
  Ir  Ir6  1  0.87158539  0.87158539  0.12841461  1.0
  Ir  Ir7  1  0.12841461  0.12841461  0.87158539  1.0
  Ir  Ir8  1  0.38331051  0.38331051  0.11668949  1.0
  Ir  Ir9  1  0.11668949  0.11668949  0.38331051  1.0

Get direct link