Li(FeO2)2

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-771571 · Space group: Cmc2_1 (#36)

Materials Project API

Basic Information

Formula

Li(FeO2)2

MP-ID

mp-771571

Elements

Sites

Density

4.2900

g/cm³

Volume

282.76

Å³

Cell a

5.8652

Cell b

5.8652

Cell c

9.5030

α Angle

90.00

β Angle

90.00

γ Angle

120.12

Space Group

Cmc2_1

Point Group

mm2

Crystal System

Orthorhombic

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
18.67	4.7515	100.0	(0,0,0,2)
19.81	4.4818	57.6	(1,-1,0,1)
19.84	4.4754	92.3	(1,0,-1,1)
25.67	3.4710	15.7	(1,-1,0,2)
25.69	3.4680	31.7	(1,0,-1,2)
33.33	2.6883	18.3	(1,-1,0,3)
33.35	2.6869	37.8	(1,0,-1,3)
35.32	2.5413	8.4	(2,-2,0,0)
35.39	2.5366	14.5	(2,0,-2,0)
35.99	2.4956	56.2	(2,-1,-1,2)
36.04	2.4922	26.1	(1,1,-2,2)
36.60	2.4550	24.9	(2,-2,0,1)
36.67	2.4508	58.0	(2,0,-2,1)
37.87	2.3757	10.1	(0,0,0,4)
40.24	2.2409	17.0	(2,-2,0,2)
40.30	2.2377	39.8	(2,0,-2,2)
45.77	1.9822	31.7	(2,-2,0,3)
45.83	1.9800	58.7	(2,0,-2,3)
48.35	1.8825	4.8	(3,-2,-1,1)
48.39	1.8810	2.1	(3,-1,-2,1)
48.45	1.8787	3.6	(2,1,-3,1)
49.37	1.8460	2.4	(2,-1,-1,4)
49.41	1.8447	1.8	(1,1,-2,4)
51.31	1.7806	4.5	(3,-2,-1,2)

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Energy Properties

Formation Energy/atom

-1.64805

eV/atom

Energy/atom

-7.16816

eV/atom

Energy above Hull

0.0762

eV/atom

Uncorrected Energy

-6.1310

eV/atom

Volume/atom

10.10

Å³

c/a Ratio

1.6202

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

36.0023

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.127320

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

2.9860

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

41.100%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.9730

smaller = more stable mixing

VEC

4.714

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

1.633

kJ/mol; negative = exothermic mixing

Entropy Norm

0.8699

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.458

Family

O-rich Multi-Component

Matrix Element

O · 0.571

Related Tasks

Related computation task IDs (2)

aaabzhii aaaefwnc

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-771571

Reference Citation

The crystal structure and related material properties of Li(FeO2)2 were obtained from the Materials Project database (MP-ID: mp-771571, 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_Li(FeO2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.86523201
_cell_length_b   5.86523201
_cell_length_c   9.50295400
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   120.12214682
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Li(FeO2)2
_chemical_formula_sum   'Li4 Fe8 O16'
_cell_volume   282.76378718
_cell_formula_units_Z   4
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
  Li  Li0  1  0.16878500  0.83121500  0.10645100  1.0
  Li  Li1  1  0.50073000  0.49927000  0.00347200  1.0
  Li  Li2  1  0.49927000  0.50073000  0.50347200  1.0
  Li  Li3  1  0.83121500  0.16878500  0.60645100  1.0
  Fe  Fe4  1  0.84001600  0.66971700  0.78591900  1.0
  Fe  Fe5  1  0.16168800  0.83831200  0.50961400  1.0
  Fe  Fe6  1  0.33028300  0.15998400  0.78591900  1.0
  Fe  Fe7  1  0.33097400  0.66902600  0.78474800  1.0
  Fe  Fe8  1  0.66902600  0.33097400  0.28474800  1.0
  Fe  Fe9  1  0.83831200  0.16168800  0.00961400  1.0
  Fe  Fe10  1  0.66971700  0.84001600  0.28591900  1.0
  Fe  Fe11  1  0.15998400  0.33028300  0.28591900  1.0
  O  O12  1  0.82287100  0.67716000  0.39868800  1.0
  O  O13  1  0.01661600  0.98338400  0.66903300  1.0
  O  O14  1  0.16157500  0.83842500  0.89307900  1.0
  O  O15  1  0.50535400  0.49464600  0.69061500  1.0
  O  O16  1  0.49464600  0.50535400  0.19061500  1.0
  O  O17  1  0.32284000  0.17712900  0.39868800  1.0
  O  O18  1  0.00530900  0.54045900  0.66054800  1.0
  O  O19  1  0.45954100  0.99469100  0.66054800  1.0
  O  O20  1  0.66444900  0.33555100  0.89712400  1.0
  O  O21  1  0.33555100  0.66444900  0.39712400  1.0
  O  O22  1  0.54045900  0.00530900  0.16054800  1.0
  O  O23  1  0.99469100  0.45954100  0.16054800  1.0
  O  O24  1  0.83842500  0.16157500  0.39307900  1.0
  O  O25  1  0.67716000  0.82287100  0.89868800  1.0
  O  O26  1  0.98338400  0.01661600  0.16903300  1.0
  O  O27  1  0.17712900  0.32284000  0.89868800  1.0

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