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Pa3(SiIr)2

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-3244994 · Space group: Cmcm (#63)

Basic Information

Formula
Pa3(SiIr)2
MP-ID
mp-3244994
Elements
3
Sites
14
Density
13.7452
g/cm³
Volume
273.92
ų
Cell a
5.6708
Å
Cell b
5.6708
Å
Cell c
13.0627
Å
α Angle
90.00
°
β Angle
90.00
°
γ Angle
139.30
°
Space Group
Cmcm
Point Group
mmm
Crystal System
Orthorhombic
Bravais Lattice
Orthorhombic C
Stability
Yes
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
16.67 5.3169 6.1 (1,-1,0)
24.07 3.6979 15.7 (1,0,0)
26.46 3.3687 3.3 (1,-1,3)
27.31 3.2657 5.4 (0,0,4)
31.75 2.8186 100.0 (1,0,3)
32.17 2.7827 32.2 (1,-1,4)
33.71 2.6584 43.6 (2,-2,0)
34.01 2.6364 25.4 (2,-1,0)
34.01 2.6364 25.4 (1,-2,0)
34.71 2.5842 6.5 (2,-1,1)
36.72 2.4478 36.6 (1,0,4)
39.73 2.2690 20.5 (2,-2,3)
39.98 2.2552 38.4 (2,-1,3)
41.48 2.1771 15.0 (0,0,6)
42.36 2.1337 1.6 (1,0,5)
43.92 2.0617 3.1 (2,-2,4)
44.15 2.0513 17.5 (2,-1,4)
44.99 2.0148 12.6 (1,-1,6)
46.02 1.9720 28.8 (1,1,0)
48.88 1.8634 1.4 (2,-2,5)
53.27 1.7198 6.7 (3,-2,3)
53.27 1.7198 6.7 (2,-3,3)
53.87 1.7019 1.0 (2,0,3)
54.35 1.6881 1.7 (1,1,4)
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Energy Properties

Formation Energy/atom
-0.90913
eV/atom
Energy/atom
-51.31403
eV/atom
Energy above Hull
0.0000
eV/atom
Uncorrected Energy
-51.3140
eV/atom
Volume/atom
19.57
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
0.2148
μB
Mag. Ordering
NM
Mag. Sites
0
Magnetization/Volume
0.000780
μB/ų

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)
Composition Info
Major / Matrix Element
Pa · 0.429
Element Family
Actinide
Solute Fraction
0.571
Interstitial Fraction
0.286

High-Entropy Alloy Features

Composite Radar (normalized)
Element-Class Share
Mix Entropy ΔS/R
1.0790
HEA criterion (>1.0 = high entropy)
Mix Entropy ΔS
8.9707
J/mol·K
Ω Parameter
6.2363
Ω > 1.1 favors solid solution
Atomic Size Mismatch δr
18.358%
δr < 6.6% favors single-phase solid solution
Electronegativity Diff Δχ
0.2949
smaller = more stable mixing
VEC
6.500
valence electron concentration, affects phase stability
Mix Enthalpy ΔH_mix
-2.954
kJ/mol; negative = exothermic mixing
Entropy Norm
0.9821
SS Former
0
Phase Tendency
IM

Traditional Material Features

ROM Blended-Feature Radar
Rating & Classification
Tier
B
Score
0.470
Family
Pa-rich Multi-Component
Matrix Element
Pa · 0.429

Related Tasks

Related computation task IDs (1)

Citation & References

Materials Project Page
https://materialsproject.org/materials/mp-3244994
Reference Citation

The crystal structure and related material properties of Pa3(SiIr)2 were obtained from the Materials Project database (MP-ID: mp-3244994, 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_Pa3(SiIr)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.67081337
_cell_length_b   5.67081314
_cell_length_c   13.06270011
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   139.30068230
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Pa3(SiIr)2
_chemical_formula_sum   'Pa6 Si4 Ir4'
_cell_volume   273.92443414
_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
  Pa  Pa0  1  0.77331737  0.22668263  0.59350080  1.0
  Pa  Pa1  1  0.51644147  0.48355853  0.25000000  1.0
  Pa  Pa2  1  0.22668263  0.77331737  0.40649920  1.0
  Pa  Pa3  1  0.77331737  0.22668263  0.90649920  1.0
  Pa  Pa4  1  0.48355853  0.51644147  0.75000000  1.0
  Pa  Pa5  1  0.22668263  0.77331737  0.09350080  1.0
  Si  Si6  1  0.05808117  0.94191883  0.59759501  1.0
  Si  Si7  1  0.05808117  0.94191883  0.90240499  1.0
  Si  Si8  1  0.94191883  0.05808117  0.40240499  1.0
  Si  Si9  1  0.94191883  0.05808117  0.09759501  1.0
  Ir  Ir10  1  0.78643883  0.21356117  0.25000000  1.0
  Ir  Ir11  1  0.21356117  0.78643883  0.75000000  1.0
  Ir  Ir12  1  0.50000000  0.50000000  0.00000000  1.0
  Ir  Ir13  1  0.50000000  0.50000000  0.50000000  1.0
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