Tm(FeO2)2

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-1077874 · Space group: R-3m (#166)

Materials Project API

Basic Information

Formula

Tm(FeO2)2

MP-ID

mp-1077874

Elements

Sites

Density

6.4714

g/cm³

Volume

88.43

Å³

Cell a

8.7015

Cell b

8.7015

Cell c

8.7015

α Angle

23.02

β Angle

23.02

γ Angle

23.02

Space Group

R-3m

Point Group

-3m

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
10.45	8.4674	66.3	(1,1,1)
20.98	4.2337	39.7	(2,2,2)
29.92	2.9865	100.0	(1,0,0)
30.55	2.9265	1.2	(1,0,1)
31.70	2.8225	47.7	(3,3,3)
32.95	2.7180	29.5	(1,1,2)
32.95	2.7180	59.0	(2,1,1)
34.66	2.5879	50.6	(2,1,2)
34.66	2.5879	25.3	(2,2,1)
38.89	2.3156	13.0	(3,2,2)
41.35	2.1835	22.7	(3,3,2)
46.81	1.9406	15.3	(3,3,4)
46.81	1.9406	30.6	(4,3,3)
49.78	1.8316	3.6	(4,4,3)
52.72	1.7363	53.7	(1,0,-1)
53.90	1.7009	2.7	(1,0,2)
53.90	1.7009	5.5	(2,1,0)
54.16	1.6935	5.8	(5,5,5)
56.13	1.6385	4.5	(4,4,5)
56.13	1.6385	8.9	(5,4,4)
57.36	1.6065	10.8	(3,2,1)
57.36	1.6065	5.4	(3,1,2)
59.50	1.5536	20.8	(5,4,5)
59.50	1.5536	10.4	(5,5,4)

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Energy Properties

Formation Energy/atom

-2.39345

eV/atom

Energy/atom

-8.28122

eV/atom

Energy above Hull

0.1003

eV/atom

Uncorrected Energy

-7.2441

eV/atom

Volume/atom

12.63

Å³

c/a Ratio

1.0000

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

9.0005

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.101780

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

45.610%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.9102

smaller = more stable mixing

VEC

6.429

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

0.415

Family

O-rich Multi-Component

Matrix Element

O · 0.571

Related Tasks

Related computation task IDs (5)

aaadmrdr aaadykzk aaaeuqmd aaaeztux aaafsrap

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-1077874

Reference Citation

The crystal structure and related material properties of Tm(FeO2)2 were obtained from the Materials Project database (MP-ID: mp-1077874, 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_Tm(FeO2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.70151655
_cell_length_b   8.70151655
_cell_length_c   8.70151718
_cell_angle_alpha   23.02014258
_cell_angle_beta   23.02014258
_cell_angle_gamma   23.02014021
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Tm(FeO2)2
_chemical_formula_sum   'Tm1 Fe2 O4'
_cell_volume   88.42822729
_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
  Tm  Tm0  1  0.00000000  0.00000000  0.00000000  1.0
  Fe  Fe1  1  0.78604600  0.78604600  0.78604600  1.0
  Fe  Fe2  1  0.21395400  0.21395400  0.21395400  1.0
  O  O3  1  0.87168900  0.87168900  0.87168900  1.0
  O  O4  1  0.12831100  0.12831100  0.12831100  1.0
  O  O5  1  0.70761200  0.70761200  0.70761200  1.0
  O  O6  1  0.29238800  0.29238800  0.29238800  1.0

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