Sm8Sb(Pd5Pt)4

High-Entropy Materials HEA

MP-ID: mp-3294984 · Space group: Pmm2 (#25)

Materials Project API

Basic Information

Formula

Sm8Sb(Pd5Pt)4

MP-ID

mp-3294984

Elements

Sites

Density

11.7620

g/cm³

Volume

597.66

Å³

Cell a

8.4201

Cell b

8.4151

Cell c

8.4349

α Angle

90.00

β Angle

90.00

γ Angle

90.00

Space Group

Pmm2

Point Group

mm2

Crystal System

Orthorhombic

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
10.49	8.4349	1.3	(0,0,1)
10.51	8.4201	1.3	(1,0,0)
10.51	8.4151	1.2	(0,1,0)
14.88	5.9522	1.4	(1,1,0)
18.24	4.8632	1.0	(1,1,1)
30.00	2.9787	2.0	(0,2,2)
30.03	2.9761	2.0	(2,2,0)
36.97	2.4316	100.0	(2,2,2)
38.50	2.3382	1.1	(2,0,3)
38.53	2.3366	1.2	(3,0,2)
38.55	2.3356	1.1	(0,3,2)
42.89	2.1087	18.3	(0,0,4)
42.97	2.1050	18.1	(4,0,0)
42.99	2.1038	18.1	(0,4,0)
44.32	2.0438	2.8	(2,2,3)
44.35	2.0427	2.9	(3,2,2)
44.35	2.0424	2.7	(2,3,2)
62.33	1.4898	10.6	(4,0,4)
62.35	1.4893	10.7	(0,4,4)
62.41	1.4880	10.6	(4,4,0)
74.67	1.2711	10.4	(2,2,6)
74.78	1.2695	10.3	(6,2,2)
74.82	1.2690	10.3	(2,6,2)
78.70	1.2158	9.6	(4,4,4)

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Energy Properties

Formation Energy/atom

-0.90996

eV/atom

Energy/atom

-29.05328

eV/atom

Energy above Hull

0.0000

eV/atom

Uncorrected Energy

-29.0533

eV/atom

Volume/atom

18.11

Å³

c/a Ratio

1.0018

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Total Mag. Moment

0.0039

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

Pd · 0.606

Element Family

4d-TM

Solute Fraction

0.394

Interstitial Fraction

0.000

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

1.0088

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

8.3869

J/mol·K

Ω Parameter

2.2458

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

13.645%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.4459

smaller = more stable mixing

VEC

8.879

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-6.381

kJ/mol; negative = exothermic mixing

Entropy Norm

0.7277

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (1)

aaahfmge

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-3294984

Reference Citation

The crystal structure and related material properties of Sm8Sb(Pd5Pt)4 were obtained from the Materials Project database (MP-ID: mp-3294984, 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_Sm8Sb(Pd5Pt)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.42013626
_cell_length_b   8.41509453
_cell_length_c   8.43484949
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   90.00000000
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Sm8Sb(Pd5Pt)4
_chemical_formula_sum   'Sm8 Sb1 Pd20 Pt4'
_cell_volume   597.66174125
_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  0.74641151  0.74691480  0.25367192  1.0
  Sm  Sm1  1  0.74641151  0.25308520  0.74632808  1.0
  Sm  Sm2  1  0.25354677  0.74588425  0.74642248  1.0
  Sm  Sm3  1  0.74641151  0.74691480  0.74632808  1.0
  Sm  Sm4  1  0.74641151  0.25308520  0.25367192  1.0
  Sm  Sm5  1  0.25354677  0.25411575  0.74642248  1.0
  Sm  Sm6  1  0.25354677  0.74588425  0.25357752  1.0
  Sm  Sm7  1  0.25354677  0.25411575  0.25357752  1.0
  Sb  Sb8  1  0.00001307  0.00000000  0.00000000  1.0
  Pd  Pd9  1  0.00049810  0.00000000  0.30667248  1.0
  Pd  Pd10  1  0.73390590  0.50000000  0.00000000  1.0
  Pd  Pd11  1  0.49992399  0.00000000  0.73449386  1.0
  Pd  Pd12  1  0.00003699  0.73565242  0.50000000  1.0
  Pd  Pd13  1  0.49992399  0.00000000  0.26550614  1.0
  Pd  Pd14  1  0.00003699  0.26434758  0.50000000  1.0
  Pd  Pd15  1  0.49996353  0.73474264  0.00000000  1.0
  Pd  Pd16  1  0.50030819  0.25433449  0.50000000  1.0
  Pd  Pd17  1  0.50030819  0.74566551  0.50000000  1.0
  Pd  Pd18  1  0.74522805  0.50000000  0.50000000  1.0
  Pd  Pd19  1  0.30885062  0.00000000  0.00000000  1.0
  Pd  Pd20  1  0.00049810  0.00000000  0.69332752  1.0
  Pd  Pd21  1  0.00003488  0.50000000  0.26588011  1.0
  Pd  Pd22  1  0.99964124  0.30881504  0.00000000  1.0
  Pd  Pd23  1  0.99964124  0.69118496  0.00000000  1.0
  Pd  Pd24  1  0.69132848  0.00000000  0.00000000  1.0
  Pd  Pd25  1  0.26504698  0.50000000  0.00000000  1.0
  Pd  Pd26  1  0.26411117  0.00000000  0.50000000  1.0
  Pd  Pd27  1  0.00003488  0.50000000  0.73411989  1.0
  Pd  Pd28  1  0.49996353  0.26525736  0.00000000  1.0
  Pt  Pt29  1  0.73634766  0.00000000  0.50000000  1.0
  Pt  Pt30  1  0.25458418  0.50000000  0.50000000  1.0
  Pt  Pt31  1  0.49997096  0.50000000  0.74568249  1.0
  Pt  Pt32  1  0.49997096  0.50000000  0.25431751  1.0

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