Sm7Pa(Pt2Pb)4

High-Entropy Materials HEA

MP-ID: mp-3292256 · Space group: Amm2 (#38)

Materials Project API

Basic Information

Formula

Sm7Pa(Pt2Pb)4

MP-ID

mp-3292256

Elements

Sites

Density

13.0172

g/cm³

Volume

468.55

Å³

Cell a

7.9879

Cell b

7.9879

Cell c

7.3451

α Angle

90.00

β Angle

90.00

γ Angle

88.72

Space Group

Amm2

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
11.08	7.9859	2.0	(1,0,0)
12.05	7.3451	1.5	(0,0,1)
15.52	5.7108	4.3	(1,1,0)
15.87	5.5851	1.7	(1,-1,0)
16.40	5.4062	2.4	(1,0,1)
24.23	3.6726	16.8	(0,0,2)
28.90	3.0890	3.2	(1,1,2)
29.10	3.0686	2.2	(1,-1,2)
31.33	2.8554	12.9	(2,2,0)
32.05	2.7925	10.7	(2,-2,0)
33.14	2.7031	63.0	(2,0,2)
34.88	2.5722	94.3	(2,1,2)
35.21	2.5487	100.0	(2,-1,2)
35.30	2.5424	58.6	(3,1,0)
35.79	2.5087	53.4	(3,-1,0)
40.00	2.2542	1.3	(2,2,2)
40.22	2.2424	1.4	(1,-1,3)
40.30	2.2380	10.7	(3,2,0)
40.58	2.2229	3.0	(2,-2,2)
41.17	2.1925	5.1	(2,-3,0)
41.17	2.1925	5.1	(3,-2,0)
43.28	2.0904	13.8	(3,1,2)
43.70	2.0715	12.6	(3,-1,2)
45.02	2.0137	1.1	(2,-1,3)

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Energy Properties

Formation Energy/atom

-1.11843

eV/atom

Energy/atom

-47.21987

eV/atom

Energy above Hull

0.0000

eV/atom

Uncorrected Energy

-47.2199

eV/atom

Volume/atom

23.43

Å³

c/a Ratio

0.9195

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Total Mag. Moment

0.0052

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 · 0.400

Element Family

5d-TM

Solute Fraction

0.600

Interstitial Fraction

0.000

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

1.2056

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

10.0236

J/mol·K

Ω Parameter

10.9415

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

12.781%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.5365

smaller = more stable mixing

VEC

7.263

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

1.374

kJ/mol; negative = exothermic mixing

Entropy Norm

0.8697

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (1)

aaahfifg

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-3292256

Reference Citation

The crystal structure and related material properties of Sm7Pa(Pt2Pb)4 were obtained from the Materials Project database (MP-ID: mp-3292256, 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_Sm7Pa(Pt2Pb)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.98789703
_cell_length_b   7.98789760
_cell_length_c   7.34511127
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   88.72397309
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Sm7Pa(Pt2Pb)4
_chemical_formula_sum   'Sm7 Pa1 Pt8 Pb4'
_cell_volume   468.54964555
_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  0.67262461  0.66342558  0.00000000  1.0
  Sm  Sm1  1  0.32221453  0.32855834  0.50000000  1.0
  Sm  Sm2  1  0.83334182  0.16665818  0.50000000  1.0
  Sm  Sm3  1  0.67144166  0.67778547  0.50000000  1.0
  Sm  Sm4  1  0.33657442  0.32737539  0.00000000  1.0
  Sm  Sm5  1  0.16905112  0.83094888  0.50000000  1.0
  Sm  Sm6  1  0.82180701  0.17819299  0.00000000  1.0
  Pa  Pa7  1  0.17067372  0.82932628  0.00000000  1.0
  Pt  Pt8  1  0.88263629  0.86930993  0.76626940  1.0
  Pt  Pt9  1  0.13069007  0.11736371  0.76626940  1.0
  Pt  Pt10  1  0.62073686  0.37926314  0.73617251  1.0
  Pt  Pt11  1  0.62073686  0.37926314  0.26382749  1.0
  Pt  Pt12  1  0.36415061  0.63584939  0.23674172  1.0
  Pt  Pt13  1  0.13069007  0.11736371  0.23373060  1.0
  Pt  Pt14  1  0.88263629  0.86930993  0.23373060  1.0
  Pt  Pt15  1  0.36415061  0.63584939  0.76325828  1.0
  Pb  Pb16  1  0.50407253  0.00115080  0.74887455  1.0
  Pb  Pb17  1  0.50407253  0.00115080  0.25112545  1.0
  Pb  Pb18  1  0.99884920  0.49592747  0.74887455  1.0
  Pb  Pb19  1  0.99884920  0.49592747  0.25112545  1.0

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