Na5Si9As3Ir19

High-Entropy Materials HEA

MP-ID: mp-3294565 · Space group: P-62m (#189)

Materials Project API

Basic Information

Formula

Na5Si9As3Ir19

MP-ID

mp-3294565

Elements

Sites

Density

12.6111

g/cm³

Volume

558.90

Å³

Cell a

12.7661

Cell b

12.7661

Cell c

3.9599

α Angle

90.00

β Angle

90.00

γ Angle

120.00

Space Group

P-62m

Point Group

-6m2

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
8.00	11.0558	5.9	(1,0,-1,0)
13.87	6.3831	37.5	(2,-1,-1,0)
16.03	5.5279	4.5	(2,0,-2,0)
21.26	4.1787	33.2	(3,-1,-2,0)
23.87	3.7280	7.4	(1,0,-1,1)
26.49	3.3650	2.6	(2,-1,-1,1)
27.96	3.1915	14.8	(4,-2,-2,0)
29.12	3.0663	2.6	(4,-1,-3,0)
31.12	2.8743	28.3	(3,-1,-2,1)
33.21	2.6977	1.7	(3,0,-3,1)
35.39	2.5364	2.4	(5,-2,-3,0)
36.15	2.4849	100.0	(4,-2,-2,1)
37.08	2.4244	25.3	(4,-1,-3,1)
37.27	2.4126	3.5	(5,-1,-4,0)
40.81	2.2112	6.7	(5,0,-5,0)
42.49	2.1277	1.9	(6,-3,-3,0)
42.49	2.1277	3.8	(3,3,-6,0)
43.31	2.0894	1.6	(6,-2,-4,0)
43.31	2.0894	3.3	(4,2,-6,0)
43.95	2.0603	14.7	(5,-1,-4,1)
45.69	1.9857	14.6	(6,-1,-5,0)
45.83	1.9800	26.1	(0,0,0,2)
47.07	1.9306	45.1	(5,0,-5,1)
48.12	1.8911	3.4	(2,-1,-1,2)

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Energy Properties

Formation Energy/atom

-0.58658

eV/atom

Energy/atom

-32.13478

eV/atom

Energy above Hull

0.0000

eV/atom

Uncorrected Energy

-32.1348

eV/atom

Volume/atom

15.52

Å³

c/a Ratio

0.3102

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Total Mag. Moment

0.0111

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.000020

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

Ir · 0.528

Element Family

5d-TM

Solute Fraction

0.472

Interstitial Fraction

0.250

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

1.1651

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

9.6868

J/mol·K

Ω Parameter

0.9525

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

15.957%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.4272

smaller = more stable mixing

VEC

6.139

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-20.438

kJ/mol; negative = exothermic mixing

Entropy Norm

0.8405

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (1)

aaahflqb

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-3294565

Reference Citation

The crystal structure and related material properties of Na5Si9As3Ir19 were obtained from the Materials Project database (MP-ID: mp-3294565, 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_Na5Si9As3Ir19
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.76612307
_cell_length_b   12.76612273
_cell_length_c   3.95989499
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   120.00000089
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na5Si9As3Ir19
_chemical_formula_sum   'Na5 Si9 As3 Ir19'
_cell_volume   558.89772155
_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  0.66666700  0.33333300  0.00000000  1.0
  Na  Na1  1  0.33333300  0.66666700  0.00000000  1.0
  Na  Na2  1  0.81548109  0.81548109  0.50000000  1.0
  Na  Na3  1  0.18451891  0.00000000  0.50000000  1.0
  Na  Na4  1  1.00000000  0.18451891  0.50000000  1.0
  Si  Si5  1  0.68632239  0.17035984  0.50000000  1.0
  Si  Si6  1  0.82964016  0.51596255  0.50000000  1.0
  Si  Si7  1  0.48403745  0.31367761  0.50000000  1.0
  Si  Si8  1  0.17035984  0.68632239  0.50000000  1.0
  Si  Si9  1  0.51596255  0.82964016  0.50000000  1.0
  Si  Si10  1  0.31367761  0.48403745  0.50000000  1.0
  Si  Si11  1  0.63071660  0.63071660  0.00000000  1.0
  Si  Si12  1  0.36928340  0.00000000  0.00000000  1.0
  Si  Si13  1  0.00000000  0.36928340  0.00000000  1.0
  As  As14  1  0.18097191  0.18097191  0.00000000  1.0
  As  As15  1  0.81902809  0.00000000  0.00000000  1.0
  As  As16  1  1.00000000  0.81902809  0.00000000  1.0
  Ir  Ir17  1  0.80295471  0.18579075  0.00000000  1.0
  Ir  Ir18  1  0.81420925  0.61716397  0.00000000  1.0
  Ir  Ir19  1  0.38283603  0.19704529  0.00000000  1.0
  Ir  Ir20  1  0.18579075  0.80295471  0.00000000  1.0
  Ir  Ir21  1  0.61716397  0.81420925  0.00000000  1.0
  Ir  Ir22  1  0.19704529  0.38283603  0.00000000  1.0
  Ir  Ir23  1  0.44763257  0.44763257  0.00000000  1.0
  Ir  Ir24  1  0.55236743  0.00000000  0.00000000  1.0
  Ir  Ir25  1  1.00000000  0.55236743  0.00000000  1.0
  Ir  Ir26  1  0.28905330  0.28905330  0.50000000  1.0
  Ir  Ir27  1  0.71094670  0.00000000  0.50000000  1.0
  Ir  Ir28  1  1.00000000  0.71094670  0.50000000  1.0
  Ir  Ir29  1  0.87496431  0.36079065  0.50000000  1.0
  Ir  Ir30  1  0.63920935  0.51417466  0.50000000  1.0
  Ir  Ir31  1  0.48582534  0.12503569  0.50000000  1.0
  Ir  Ir32  1  0.36079065  0.87496431  0.50000000  1.0
  Ir  Ir33  1  0.51417466  0.63920935  0.50000000  1.0
  Ir  Ir34  1  0.12503569  0.48582534  0.50000000  1.0
  Ir  Ir35  1  0.00000000  0.00000000  0.00000000  1.0

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