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Ag9(SI)4

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-676430 · Space group: Cm (#8)

Basic Information

Formula
Ag9(SI)4
MP-ID
mp-676430
Elements
3
Sites
17
Density
6.4966
g/cm³
Volume
410.68
ų
Cell a
4.1286
Å
Cell b
4.1286
Å
Cell c
27.1251
Å
α Angle
89.05
°
β Angle
89.05
°
γ Angle
62.67
°
Space Group
Cm
Point Group
m
Crystal System
Monoclinic
Bravais Lattice
Monoclinic C
Stability
No
Packing Fraction
0.5240

X-ray Diffraction

Diffraction Pattern
X-axis: 2θ (°); Y-axis: relative intensity; CuKa ; λ=1.5406 Å
Diffraction Peaks (Top 24)
2θd (Å)Ihkl
3.26 27.1199 6.2 (0,0,0,1)
19.64 4.5200 1.6 (0,0,0,6)
24.27 3.6676 3.1 (1,0,-1,0)
25.09 3.5495 4.2 (1,0,-1,2)
25.26 3.5257 1.5 (1,1,-2,0)
25.41 3.5051 3.9 (1,1,-2,1)
25.99 3.4286 3.8 (1,1,-2,2)
26.13 3.4106 7.8 (1,0,-1,3)
27.53 3.2396 14.6 (1,0,-1,4)
27.77 3.2123 26.6 (1,0,-1,-4)
28.30 3.1533 2.5 (1,1,-2,4)
28.77 3.1034 7.6 (1,1,-2,-4)
29.26 3.0526 4.8 (1,0,-1,5)
29.54 3.0240 100.0 (1,0,-1,-5)
29.65 3.0133 1.5 (0,0,0,9)
29.96 2.9828 29.9 (1,1,-2,5)
30.51 2.9301 11.2 (1,1,-2,-5)
31.57 2.8340 3.3 (1,0,-1,-6)
31.89 2.8067 27.1 (1,1,-2,6)
32.51 2.7541 3.2 (1,1,-2,-6)
33.82 2.6501 8.5 (1,0,-1,-7)
34.05 2.6333 6.5 (1,1,-2,7)
35.89 2.5021 1.8 (1,0,-1,8)
36.27 2.4770 9.9 (1,0,-1,-8)
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Energy Properties

Formation Energy/atom
-0.20639
eV/atom
Energy/atom
-3.04357
eV/atom
Energy above Hull
0.1168
eV/atom
Uncorrected Energy
-2.8360
eV/atom
Volume/atom
24.16
ų
c/a Ratio
-

Electronic Properties

Metallic
Metal
Band Gap
0
eV
Direct Gap
No
CBM
N/A
eV

Magnetic Properties

Magnetic
No
Total Mag. Moment
0.0010
μB
Mag. Ordering
NM
Mag. Sites
0
Magnetization/Volume
0.000000
μB/ų

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)
Composition Info
Major / Matrix Element
Ag · 0.529
Element Family
4d-TM
Solute Fraction
0.471
Interstitial Fraction
0.000

High-Entropy Alloy Features

Composite Radar (normalized)
Element-Class Share
Mix Entropy ΔS/R
1.0176
HEA criterion (>1.0 = high entropy)
Mix Entropy ΔS
8.4604
J/mol·K
Ω Parameter
0.4302
Ω > 1.1 favors solid solution
Atomic Size Mismatch δr
12.702%
δr < 6.6% favors single-phase solid solution
Electronegativity Diff Δχ
0.3455
smaller = more stable mixing
VEC
8.412
valence electron concentration, affects phase stability
Mix Enthalpy ΔH_mix
-16.445
kJ/mol; negative = exothermic mixing
Entropy Norm
0.9263
SS Former
0
Phase Tendency
AM

Traditional Material Features

ROM Blended-Feature Radar
Rating & Classification
Tier
B
Score
0.534
Family
Ag-rich Multi-Component
Matrix Element
Ag · 0.529

Related Tasks

Related computation task IDs (3)

Citation & References

Materials Project Page
https://materialsproject.org/materials/mp-676430
Reference Citation

The crystal structure and related material properties of Ag9(SI)4 were obtained from the Materials Project database (MP-ID: mp-676430, 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

BibTeX
@article{Horton2025,
  author  = {Horton, Matthew K. and Huck, Patrick and Yang, Ruo Xi and Munro, Jason M. and Dwaraknath, Shyam and Ganose, Alex M. and Kingsbury, Ryan S. and Wen, Mingjian and Shen, Jimmy X. and Mathis, Tyler S. and Kaplan, Aaron D. and Berket, Karlo and Riebesell, Janosh and George, Janine and Rosen, Andrew S. and Spotte-Smith, Evan W. C. and McDermott, Matthew J. and Cohen, Orion A. and Dunn, Alex and Kuner, Matthew C. and Rignanese, Gian-Marco and Petretto, Guido and Waroquiers, David and Griffin, Sinead M. and Neaton, Jeffrey B. and Chrzan, Daryl C. and Asta, Mark and Hautier, Geoffroy and Cholia, Shreyas and Ceder, Gerbrand and Ong, Shyue Ping and Jain, Anubhav and Persson, Kristin A.},
  title   = {Accelerated data-driven materials science with the Materials Project},
  journal = {Nature Materials},
  year    = {2025},
  volume  = {24},
  number  = {10},
  pages   = {1522--1532},
  month   = {oct},
  doi     = {10.1038/s41563-025-02272-0},
  issn    = {1476-4660},
  url     = {https://doi.org/10.1038/s41563-025-02272-0},
  abstract = {The Materials Project was launched formally in 2011 to drive materials discovery forwards through high-throughput computation and open data. More than a decade later, the Materials Project has become an indispensable tool used by more than 600,000 materials researchers around the world. This Perspective describes how the Materials Project, as a data platform and a software ecosystem, has helped to shape research in data-driven materials science. We cover how sustainable software and computational methods have accelerated materials design while becoming more open source and collaborative in nature. Next, we present cases where the Materials Project was used to understand and discover functional materials. We then describe our efforts to meet the needs of an expanding user base, through technical infrastructure updates ranging from data architecture and cloud resources to interactive web applications. Finally, we discuss opportunities to better aid the research community, with the vision that more accessible and easy-to-understand materials data will result in democratized materials knowledge and an increasingly collaborative community.}
}

3D Crystal Structure Rendering

Loading 3D structure…

Style: Ball & Stick
Raw CIF Data
# generated using pymatgen
data_Ag9(SI)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.12861455
_cell_length_b   4.12861455
_cell_length_c   27.12509033
_cell_angle_alpha   89.04633398
_cell_angle_beta   89.04633398
_cell_angle_gamma   62.67108110
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ag9(SI)4
_chemical_formula_sum   'Ag9 S4 I4'
_cell_volume   410.67562231
_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
  Ag  Ag0  1  0.28933900  0.28933900  0.02730700  1.0
  Ag  Ag1  1  0.91664300  0.91664300  0.17246700  1.0
  Ag  Ag2  1  0.56176700  0.56176700  0.31102000  1.0
  Ag  Ag3  1  0.20794200  0.20794200  0.44921600  1.0
  Ag  Ag4  1  0.84144300  0.84144300  0.59286300  1.0
  Ag  Ag5  1  0.48284600  0.48284600  0.68205600  1.0
  Ag  Ag6  1  0.29736600  0.29736600  0.78275600  1.0
  Ag  Ag7  1  0.90831300  0.90831300  0.84003200  1.0
  Ag  Ag8  1  0.64717500  0.64717500  0.93821400  1.0
  S  S9  1  0.18162800  0.18162800  0.63252400  1.0
  S  S10  1  0.94899700  0.94899700  0.98805700  1.0
  S  S11  1  0.76074600  0.76074600  0.73849800  1.0
  S  S12  1  0.36501600  0.36501600  0.88210300  1.0
  I  I13  1  0.58328200  0.58328200  0.10871900  1.0
  I  I14  1  0.23441600  0.23441600  0.24366600  1.0
  I  I15  1  0.88842600  0.88842600  0.37866700  1.0
  I  I16  1  0.54090400  0.54090400  0.51308400  1.0
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