Sm8Si(PdPt7)3

High-Entropy Materials HEA

MP-ID: mp-3293370 · Space group: Pmm2 (#25)

Materials Project API

Basic Information

Formula

Sm8Si(PdPt7)3

MP-ID

mp-3293370

Elements

Sites

Density

15.9415

g/cm³

Volume

588.22

Å³

Cell a

8.3805

Cell b

8.3641

Cell c

8.3916

α Angle

90.00

β Angle

90.00

γ Angle

90.00

Space Group

Pmm2

Point Group

mm2

Crystal System

Orthorhombic

Bravais Lattice

Stability

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 12)

2θ	d (Å)	I	hkl
10.56	8.3805	1.2	(1,0,0)
37.17	2.4187	100.0	(2,2,2)
43.12	2.0979	16.7	(0,0,4)
43.18	2.0951	16.7	(4,0,0)
43.27	2.0910	16.5	(0,4,0)
62.67	1.4825	10.6	(4,0,4)
62.74	1.4810	10.5	(0,4,4)
62.78	1.4800	10.5	(4,4,0)
75.13	1.2646	11.8	(2,2,6)
75.21	1.2633	11.8	(6,2,2)
75.34	1.2615	11.7	(2,6,2)
79.21	1.2094	10.3	(4,4,4)

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Energy Properties

Formation Energy/atom

-1.04769

eV/atom

Energy/atom

-43.37377

eV/atom

Energy above Hull

0.0001

eV/atom

Uncorrected Energy

-43.3738

eV/atom

Volume/atom

17.82

Å³

c/a Ratio

1.0013

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Total Mag. Moment

0.0072

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

Pt · 0.636

Element Family

5d-TM

Solute Fraction

0.364

Interstitial Fraction

0.030

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

0.9551

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

7.9407

J/mol·K

Ω Parameter

2.3934

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

13.757%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.4699

smaller = more stable mixing

VEC

8.848

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-6.112

kJ/mol; negative = exothermic mixing

Entropy Norm

0.6890

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (1)

aaahfjwc

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-3293370

Reference Citation

The crystal structure and related material properties of Sm8Si(PdPt7)3 were obtained from the Materials Project database (MP-ID: mp-3293370, 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

Loading 3D structure…

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Raw CIF Data

# generated using pymatgen
data_Sm8Si(PdPt7)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.38053493
_cell_length_b   8.36409407
_cell_length_c   8.39161313
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   90.00000000
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Sm8Si(PdPt7)3
_chemical_formula_sum   'Sm8 Si1 Pd3 Pt21'
_cell_volume   588.21501071
_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
  Sm  Sm0  1  0.25249266  0.25270842  0.25264094  1.0
  Sm  Sm1  1  0.74739922  0.74732349  0.74705511  1.0
  Sm  Sm2  1  0.74739922  0.74732349  0.25294489  1.0
  Sm  Sm3  1  0.74739922  0.25267651  0.74705511  1.0
  Sm  Sm4  1  0.25249266  0.25270842  0.74735906  1.0
  Sm  Sm5  1  0.25249266  0.74729158  0.25264094  1.0
  Sm  Sm6  1  0.25249266  0.74729158  0.74735906  1.0
  Sm  Sm7  1  0.74739922  0.25267651  0.25294489  1.0
  Si  Si8  1  0.00071777  0.00000000  0.00000000  1.0
  Pd  Pd9  1  0.74168043  0.00000000  0.50000000  1.0
  Pd  Pd10  1  0.99985010  0.50000000  0.25897594  1.0
  Pd  Pd11  1  0.99985010  0.50000000  0.74102406  1.0
  Pt  Pt12  1  0.25794553  0.50000000  0.00000000  1.0
  Pt  Pt13  1  0.74218811  0.50000000  0.00000000  1.0
  Pt  Pt14  1  0.00006746  0.25882295  0.50000000  1.0
  Pt  Pt15  1  0.50014335  0.25899041  0.00000000  1.0
  Pt  Pt16  1  0.00006746  0.74117705  0.50000000  1.0
  Pt  Pt17  1  0.50014335  0.74100959  0.00000000  1.0
  Pt  Pt18  1  0.49985918  0.00000000  0.25864243  1.0
  Pt  Pt19  1  0.25833328  0.00000000  0.50000000  1.0
  Pt  Pt20  1  0.49985918  0.00000000  0.74135757  1.0
  Pt  Pt21  1  0.25173664  0.50000000  0.50000000  1.0
  Pt  Pt22  1  0.74809703  0.50000000  0.50000000  1.0
  Pt  Pt23  1  0.49983012  0.25273281  0.50000000  1.0
  Pt  Pt24  1  0.49983012  0.74726719  0.50000000  1.0
  Pt  Pt25  1  0.50013412  0.50000000  0.25253849  1.0
  Pt  Pt26  1  0.50013412  0.50000000  0.74746151  1.0
  Pt  Pt27  1  0.28311396  0.00000000  0.00000000  1.0
  Pt  Pt28  1  0.71747547  0.00000000  0.00000000  1.0
  Pt  Pt29  1  0.99984399  0.28375541  0.00000000  1.0
  Pt  Pt30  1  0.99984399  0.71624459  0.00000000  1.0
  Pt  Pt31  1  0.99984380  0.00000000  0.28324844  1.0
  Pt  Pt32  1  0.99984380  0.00000000  0.71675156  1.0

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