Sm(FeO2)2

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-793791 · Space group: R3m (#160)

Materials Project API

Basic Information

Formula

Sm(FeO2)2

MP-ID

mp-793791

Elements

Sites

Density

5.6962

g/cm³

Volume

95.05

Å³

Cell a

8.6553

Cell b

8.6553

Cell c

8.6553

α Angle

24.11

β Angle

24.11

γ Angle

24.11

Space Group

R3m

Point Group

Crystal System

Trigonal

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 24)

2θ	d (Å)	I	hkl
10.53	8.3999	48.5	(1,1,1)
21.15	4.1999	41.4	(2,2,2)
28.74	3.1065	39.6	(0,0,1)
28.74	3.1065	79.1	(1,0,0)
31.92	2.8034	100.0	(2,1,1)
31.96	2.8000	47.9	(3,3,3)
33.70	2.6592	89.3	(2,2,1)
38.10	2.3622	11.9	(3,2,2)
40.63	2.2204	20.4	(3,3,2)
46.25	1.9630	54.9	(4,3,3)
49.29	1.8487	4.5	(4,4,3)
50.50	1.8073	69.3	(1,0,-1)
51.74	1.7669	6.9	(2,1,0)
54.63	1.6800	6.9	(5,5,5)
55.34	1.6602	18.7	(3,2,1)
55.78	1.6481	11.4	(5,4,4)
59.14	1.5622	4.9	(1,1,-1)
59.14	1.5622	9.8	(1,-1,1)
59.21	1.5604	34.8	(5,5,4)
61.00	1.5190	15.5	(2,2,0)
61.02	1.5185	43.2	(4,3,2)
62.09	1.4948	16.1	(3,1,1)
64.97	1.4354	2.2	(3,3,1)
66.45	1.4069	1.4	(6,5,5)

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Energy Properties

Formation Energy/atom

-2.26675

eV/atom

Energy/atom

-8.18825

eV/atom

Energy above Hull

0.1593

eV/atom

Uncorrected Energy

-7.1511

eV/atom

Volume/atom

13.58

Å³

c/a Ratio

1.0000

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

9.0061

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.094750

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

O · 0.571

Element Family

Metalloid-Nonmetal

Solute Fraction

0.429

Interstitial Fraction

0.000

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

0.9557

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

7.9457

J/mol·K

Ω Parameter

0.0000

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

47.706%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.9282

smaller = more stable mixing

VEC

5.429

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

0.000

kJ/mol; negative = exothermic mixing

Entropy Norm

0.8699

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.376

Family

O-rich Multi-Component

Matrix Element

O · 0.571

Related Tasks

Related computation task IDs (5)

aaadchqh aaadoqzi aaadungi aaaeqkbt aaafbbap

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-793791

Reference Citation

The crystal structure and related material properties of Sm(FeO2)2 were obtained from the Materials Project database (MP-ID: mp-793791, 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_Sm(FeO2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.65524793
_cell_length_b   8.65524793
_cell_length_c   8.65524789
_cell_angle_alpha   24.10573370
_cell_angle_beta   24.10573370
_cell_angle_gamma   24.10573168
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Sm(FeO2)2
_chemical_formula_sum   'Sm1 Fe2 O4'
_cell_volume   95.04792221
_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  0.99984000  0.99984000  0.99984000  1.0
  Fe  Fe1  1  0.21133100  0.21133100  0.21133100  1.0
  Fe  Fe2  1  0.78666300  0.78666300  0.78666300  1.0
  O  O3  1  0.12170500  0.12170500  0.12170500  1.0
  O  O4  1  0.29226200  0.29226200  0.29226200  1.0
  O  O5  1  0.71009500  0.71009500  0.71009500  1.0
  O  O6  1  0.86490000  0.86490000  0.86490000  1.0

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