SrAl8SiAu4

High-Entropy Materials HEA

MP-ID: mp-3292342 · Space group: I4/mmm (#139)

Materials Project API

Basic Information

Formula

SrAl8SiAu4

MP-ID

mp-3292342

Elements

Sites

Density

7.0650

g/cm³

Volume

526.21

Å³

Cell a

6.0343

Cell b

6.0343

Cell c

15.0683

α Angle

101.55

β Angle

101.55

γ Angle

90.00

Space Group

I4/mmm

Point Group

4/mmm

Crystal System

Tetragonal

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
6.12	14.4516	8.4	(0,0,1)
15.00	5.9069	2.4	(1,0,-1)
17.34	5.1140	13.2	(1,0,-2)
18.42	4.8172	1.7	(0,0,3)
21.29	4.1743	3.7	(0,1,-3)
21.29	4.1743	11.0	(1,0,-3)
24.22	3.6741	91.0	(1,-1,2)
24.22	3.6741	30.3	(1,1,1)
24.64	3.6129	6.0	(0,0,4)
26.15	3.4076	8.1	(1,0,-4)
27.93	3.1941	100.0	(1,-1,3)
29.61	3.0171	58.4	(2,0,-1)
30.94	2.8903	13.4	(0,0,5)
31.56	2.8350	2.1	(1,0,-5)
32.15	2.7842	1.9	(2,0,-3)
32.47	2.7573	4.6	(1,1,-5)
32.47	2.7573	4.6	(1,-1,-4)
34.52	2.5986	5.2	(2,-1,1)
35.09	2.5570	7.0	(2,0,-4)
36.75	2.4453	7.8	(2,-1,-3)
37.59	2.3930	1.6	(1,1,-6)
38.89	2.3158	16.1	(2,0,-5)
38.89	2.3158	5.4	(0,2,3)
39.91	2.2589	2.8	(1,-2,4)

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Energy Properties

Formation Energy/atom

-0.54660

eV/atom

Energy/atom

-20.55489

eV/atom

Energy above Hull

0.0000

eV/atom

Uncorrected Energy

-20.5549

eV/atom

Volume/atom

18.79

Å³

c/a Ratio

2.4971

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Total Mag. Moment

0.0029

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.000010

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

Al · 0.571

Element Family

PostTransition-Noble

Solute Fraction

0.429

Interstitial Fraction

0.071

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

1.0547

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

8.7689

J/mol·K

Ω Parameter

0.4673

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

11.385%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.4764

smaller = more stable mixing

VEC

5.286

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-20.846

kJ/mol; negative = exothermic mixing

Entropy Norm

0.7608

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (1)

aaahfiio

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-3292342

Reference Citation

The crystal structure and related material properties of SrAl8SiAu4 were obtained from the Materials Project database (MP-ID: mp-3292342, 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_SrAl8SiAu4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.03424533
_cell_length_b   6.03424508
_cell_length_c   15.06832558
_cell_angle_alpha   101.55038168
_cell_angle_beta   101.55037844
_cell_angle_gamma   90.00000248
_symmetry_Int_Tables_number   1
_chemical_formula_structural   SrAl8SiAu4
_chemical_formula_sum   'Sr2 Al16 Si2 Au8'
_cell_volume   526.21285222
_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
  Sr  Sr0  1  0.75000100  0.25000000  0.50000000  1.0
  Sr  Sr1  1  0.25000000  0.75000100  0.50000000  1.0
  Al  Al2  1  0.30140228  0.30140228  0.10413971  1.0
  Al  Al3  1  0.80273744  0.30140228  0.10413971  1.0
  Al  Al4  1  0.30140228  0.80273744  0.10413971  1.0
  Al  Al5  1  0.80273744  0.80273744  0.10413971  1.0
  Al  Al6  1  0.40451428  0.40451428  0.30953195  1.0
  Al  Al7  1  0.90501667  0.40451428  0.30953195  1.0
  Al  Al8  1  0.40451428  0.90501667  0.30953195  1.0
  Al  Al9  1  0.90501667  0.90501667  0.30953195  1.0
  Al  Al10  1  0.09498233  0.09498233  0.69046805  1.0
  Al  Al11  1  0.59548572  0.09498233  0.69046805  1.0
  Al  Al12  1  0.09498233  0.59548572  0.69046805  1.0
  Al  Al13  1  0.59548572  0.59548572  0.69046805  1.0
  Al  Al14  1  0.19726356  0.19726356  0.89586029  1.0
  Al  Al15  1  0.69859672  0.19726356  0.89586029  1.0
  Al  Al16  1  0.19726356  0.69859672  0.89586029  1.0
  Al  Al17  1  0.69859672  0.69859672  0.89586029  1.0
  Si  Si18  1  0.20660485  0.20660485  0.41321070  1.0
  Si  Si19  1  0.79339515  0.79339515  0.58679030  1.0
  Au  Au20  1  0.00000000  0.00000000  0.00000000  1.0
  Au  Au21  1  0.50000100  0.50000100  0.00000000  1.0
  Au  Au22  1  0.60368715  0.10368715  0.20737231  1.0
  Au  Au23  1  0.10368715  0.60368715  0.20737231  1.0
  Au  Au24  1  0.70568449  0.70568449  0.41136698  1.0
  Au  Au25  1  0.29431651  0.29431651  0.58863302  1.0
  Au  Au26  1  0.89631385  0.39631285  0.79262669  1.0
  Au  Au27  1  0.39631285  0.89631385  0.79262669  1.0

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