Sc4Al18Ir5Au

High-Entropy Materials HEA

MP-ID: mp-3295081 · Space group: C2/m (#12)

Materials Project API

Basic Information

Formula

Sc4Al18Ir5Au

MP-ID

mp-3295081

Elements

Sites

Density

6.7645

g/cm³

Volume

447.64

Å³

Cell a

7.4597

Cell b

7.4597

Cell c

9.2691

α Angle

90.02

β Angle

90.02

γ Angle

119.79

Space Group

C2/m

Point Group

2/m

Crystal System

Monoclinic

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
19.15	4.6345	100.0	(0,0,0,2)
23.78	3.7417	56.3	(1,1,-2,0)
23.86	3.7298	55.7	(1,-2,1,0)
23.86	3.7298	55.7	(2,-1,-1,0)
30.70	2.9125	35.8	(1,1,-2,-2)
30.72	2.9101	34.9	(1,1,-2,2)
30.76	2.9063	68.6	(2,-1,-1,-2)
30.78	2.9051	71.7	(2,-1,-1,2)
33.85	2.6481	4.0	(2,-2,0,2)
37.74	2.3834	3.8	(1,1,-2,-3)
37.78	2.3814	3.3	(1,1,-2,3)
37.80	2.3799	6.8	(2,-1,-1,-3)
37.82	2.3789	8.0	(2,-1,-1,3)
38.09	2.3625	1.4	(3,-1,-2,1)
38.86	2.3173	34.2	(0,0,0,4)
41.70	2.1661	1.3	(2,1,-3,-2)
41.73	2.1646	1.7	(2,1,-3,2)
41.84	2.1590	2.1	(3,-2,-1,2)
41.86	2.1580	36.5	(0,3,-3,0)
41.86	2.1580	36.5	(3,0,-3,0)
42.00	2.1512	35.7	(3,-3,0,0)
46.05	1.9708	14.6	(1,1,-2,-4)
46.09	1.9693	14.8	(1,1,-2,4)
46.11	1.9687	14.9	(1,-2,1,4)

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Energy Properties

Formation Energy/atom

-0.86552

eV/atom

Energy/atom

-17.97814

eV/atom

Energy above Hull

0.0000

eV/atom

Uncorrected Energy

-17.9781

eV/atom

Volume/atom

15.99

Å³

c/a Ratio

1.2426

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Total Mag. Moment

0.0004

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

Al · 0.643

Element Family

PostTransition-Noble

Solute Fraction

0.357

Interstitial Fraction

0.000

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

0.9887

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

8.2198

J/mol·K

Ω Parameter

0.4015

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

5.275%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.3023

smaller = more stable mixing

VEC

4.357

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-28.579

kJ/mol; negative = exothermic mixing

Entropy Norm

0.7132

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (1)

aaahfmjx

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-3295081

Reference Citation

The crystal structure and related material properties of Sc4Al18Ir5Au were obtained from the Materials Project database (MP-ID: mp-3295081, 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_Sc4Al18Ir5Au
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.45973086
_cell_length_b   7.45973195
_cell_length_c   9.26906716
_cell_angle_alpha   90.02440901
_cell_angle_beta   90.02441073
_cell_angle_gamma   119.78981026
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Sc4Al18Ir5Au
_chemical_formula_sum   'Sc4 Al18 Ir5 Au1'
_cell_volume   447.63994590
_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
  Sc  Sc0  1  0.99545472  0.67308598  0.75181537  1.0
  Sc  Sc1  1  0.00454528  0.32691402  0.24818463  1.0
  Sc  Sc2  1  0.67308598  0.99545472  0.75181537  1.0
  Sc  Sc3  1  0.32691402  0.00454528  0.24818463  1.0
  Al  Al4  1  0.13245220  0.13245220  0.75537741  1.0
  Al  Al5  1  0.86754780  0.86754780  0.24462259  1.0
  Al  Al6  1  0.99899254  0.34289268  0.57975438  1.0
  Al  Al7  1  0.00100746  0.65710732  0.42024562  1.0
  Al  Al8  1  0.00200360  0.66507396  0.07429090  1.0
  Al  Al9  1  0.33492604  0.99799640  0.92570910  1.0
  Al  Al10  1  0.99799640  0.33492604  0.92570910  1.0
  Al  Al11  1  0.66507396  0.00200360  0.07429090  1.0
  Al  Al12  1  0.65710732  0.00100746  0.42024562  1.0
  Al  Al13  1  0.34289268  0.99899254  0.57975438  1.0
  Al  Al14  1  0.33187785  0.33187785  0.05763767  1.0
  Al  Al15  1  0.66812215  0.66812215  0.94236233  1.0
  Al  Al16  1  0.66047906  0.66047906  0.56276681  1.0
  Al  Al17  1  0.33952094  0.33952094  0.43723319  1.0
  Al  Al18  1  0.33874073  0.55279842  0.75095075  1.0
  Al  Al19  1  0.66125927  0.44720158  0.24904925  1.0
  Al  Al20  1  0.55279842  0.33874073  0.75095075  1.0
  Al  Al21  1  0.44720158  0.66125927  0.24904925  1.0
  Ir  Ir22  1  0.67199834  0.32800166  0.50000000  1.0
  Ir  Ir23  1  0.32800166  0.67199834  0.50000000  1.0
  Ir  Ir24  1  0.32798772  0.67201228  0.00000000  1.0
  Ir  Ir25  1  0.67201228  0.32798772  1.00000000  1.0
  Ir  Ir26  1  0.00000000  0.00000000  0.00000000  1.0
  Au  Au27  1  0.00000000  0.00000000  0.50000000  1.0

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