SmPa(CoSi2)2

High-Entropy Materials HEA

MP-ID: mp-3249464 · Space group: Amm2 (#38)

Materials Project API

Basic Information

Formula

SmPa(CoSi2)2

MP-ID

mp-3249464

Elements

Sites

Density

7.8171

g/cm³

Volume

129.92

Å³

Cell a

8.3980

Cell b

8.3980

Cell c

3.9747

α Angle

90.00

β Angle

90.00

γ Angle

152.39

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
10.85	8.1554	28.8	(1,-1,0)
21.80	4.0777	84.7	(2,-2,0)
22.37	3.9747	5.4	(0,0,1)
22.85	3.8921	63.7	(1,0,0)
24.92	3.5730	87.1	(1,-1,1)
27.65	3.2261	7.0	(1,-2,0)
27.65	3.2261	7.0	(2,-1,0)
31.43	2.8463	45.6	(2,-2,1)
32.19	2.7809	78.7	(0,1,1)
32.19	2.7809	78.7	(1,0,1)
32.95	2.7185	12.0	(3,-3,0)
35.48	2.5300	69.8	(2,-3,0)
35.48	2.5300	69.8	(3,-2,0)
35.85	2.5049	100.0	(1,-2,1)
35.85	2.5049	100.0	(2,-1,1)
40.19	2.2439	77.2	(3,-3,1)
42.35	2.1343	15.2	(2,-3,1)
42.35	2.1343	15.2	(3,-2,1)
44.43	2.0389	5.6	(4,-4,0)
45.00	2.0144	1.1	(3,-4,0)
45.00	2.0144	1.1	(4,-3,0)
45.25	2.0040	59.0	(1,1,0)
45.65	1.9874	57.5	(0,0,2)
46.67	1.9461	1.9	(2,0,0)

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Energy Properties

Formation Energy/atom

-0.72671

eV/atom

Energy/atom

-21.74577

eV/atom

Energy above Hull

0.0000

eV/atom

Uncorrected Energy

-21.7458

eV/atom

Volume/atom

16.24

Å³

c/a Ratio

0.4733

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Total Mag. Moment

0.0000

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.000000

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

Si · 0.500

Element Family

Metalloid-Nonmetal

Solute Fraction

0.500

Interstitial Fraction

0.500

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

1.2130

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

10.0849

J/mol·K

Ω Parameter

0.9703

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

20.263%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.2556

smaller = more stable mixing

VEC

5.714

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-17.500

kJ/mol; negative = exothermic mixing

Entropy Norm

0.8750

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (1)

aaahcwxk

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-3249464

Reference Citation

The crystal structure and related material properties of SmPa(CoSi2)2 were obtained from the Materials Project database (MP-ID: mp-3249464, 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_SmPa(CoSi2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.39802986
_cell_length_b   8.39803146
_cell_length_c   3.97473151
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   152.38963151
_symmetry_Int_Tables_number   1
_chemical_formula_structural   SmPa(CoSi2)2
_chemical_formula_sum   'Sm1 Pa1 Co2 Si4'
_cell_volume   129.91867774
_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  0.89308198  0.10691802  0.75000000  1.0
  Pa  Pa1  1  0.11021493  0.88978507  0.25000000  1.0
  Co  Co2  1  0.67566433  0.32433567  0.75000000  1.0
  Co  Co3  1  0.31976787  0.68023213  0.25000000  1.0
  Si  Si4  1  0.75047993  0.24952007  0.25000000  1.0
  Si  Si5  1  0.24982173  0.75017827  0.75000000  1.0
  Si  Si6  1  0.54127714  0.45872286  0.75000000  1.0
  Si  Si7  1  0.45969109  0.54030891  0.25000000  1.0

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