Li7Fe(O2F)2

High-Entropy Materials HEA

MP-ID: mp-856325 · Space group: P1 (#1)

Materials Project API

Basic Information

Formula

Li7Fe(O2F)2

MP-ID

mp-856325

Elements

Sites

Density

2.4885

g/cm³

Volume

275.49

Å³

Cell a

5.5271

Cell b

5.8951

Cell c

9.9447

α Angle

105.44

β Angle

88.29

γ Angle

117.46

Space Group

Point Group

Crystal System

Triclinic

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
9.28	9.5288	32.1	(0,0,1)
17.48	5.0724	28.7	(0,1,-1)
17.69	5.0143	84.3	(0,1,0)
18.20	4.8752	1.9	(1,0,0)
18.48	4.8023	12.4	(1,-1,0)
18.62	4.7644	60.2	(0,0,2)
19.27	4.6059	3.6	(1,-1,1)
19.53	4.5452	74.3	(1,0,-1)
21.36	4.1605	50.2	(1,0,1)
21.77	4.0829	10.9	(0,1,-2)
22.06	4.0287	46.9	(1,-1,-1)
22.26	3.9935	4.1	(0,1,1)
24.03	3.7027	36.0	(1,-1,2)
27.56	3.2361	10.2	(1,0,2)
28.09	3.1763	11.9	(0,0,3)
28.49	3.1328	1.3	(1,-1,-2)
28.67	3.1138	25.0	(0,1,-3)
29.31	3.0476	14.0	(0,1,2)
30.28	2.9521	100.0	(1,1,-1)
31.02	2.8828	1.6	(1,1,0)
31.08	2.8775	8.3	(1,-1,3)
31.53	2.8376	10.9	(1,-2,0)
31.91	2.8044	4.3	(1,0,-3)
32.27	2.7742	10.3	(1,-2,2)

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Energy Properties

Formation Energy/atom

-0.86963

eV/atom

Energy/atom

-4.11631

eV/atom

Energy above Hull

1.4931

eV/atom

Uncorrected Energy

-3.6929

eV/atom

Volume/atom

9.84

Å³

c/a Ratio

1.7993

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

8.6322

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.031330

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

Li · 0.500

Element Family

Alkali-AlkEarth

Solute Fraction

0.500

Interstitial Fraction

0.000

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

1.1710

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

9.7357

J/mol·K

Ω Parameter

2.5864

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

42.214%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

1.2826

smaller = more stable mixing

VEC

2.929

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

1.429

kJ/mol; negative = exothermic mixing

Entropy Norm

0.8447

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (2)

aaabxdip aaabxeow

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-856325

Reference Citation

The crystal structure and related material properties of Li7Fe(O2F)2 were obtained from the Materials Project database (MP-ID: mp-856325, 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_Li7Fe(O2F)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.52704700
_cell_length_b   5.89510329
_cell_length_c   9.94473146
_cell_angle_alpha   105.44390164
_cell_angle_beta   88.29325518
_cell_angle_gamma   117.46102347
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Li7Fe(O2F)2
_chemical_formula_sum   'Li14 Fe2 O8 F4'
_cell_volume   275.48933247
_cell_formula_units_Z   2
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  0.02424800  0.15489300  0.77327100  1.0
  Li  Li1  1  0.49676300  0.14670400  0.24855500  1.0
  Li  Li2  1  0.53499500  0.43892600  0.61797200  1.0
  Li  Li3  1  0.96801900  0.56123500  0.88094000  1.0
  Li  Li4  1  0.02357100  0.18059000  0.55780900  1.0
  Li  Li5  1  0.53642300  0.28730400  0.04368100  1.0
  Li  Li6  1  0.98571700  0.33283100  0.32357400  1.0
  Li  Li7  1  0.46773400  0.77921100  0.94244800  1.0
  Li  Li8  1  0.96786100  0.75274700  0.45944200  1.0
  Li  Li9  1  0.00878800  0.40314800  0.12157400  1.0
  Li  Li10  1  0.49546600  0.61008300  0.38513400  1.0
  Li  Li11  1  0.43768300  0.79992900  0.73156500  1.0
  Li  Li12  1  0.02742200  0.87023100  0.24988500  1.0
  Li  Li13  1  0.52103400  0.67538800  0.17574200  1.0
  Fe  Fe14  1  0.06081800  0.95905200  0.02336900  1.0
  Fe  Fe15  1  0.49595100  0.08929500  0.45607700  1.0
  O  O16  1  0.30119300  0.85614500  0.19668900  1.0
  O  O17  1  0.16840600  0.81258500  0.96120300  1.0
  O  O18  1  0.67572700  0.88194800  0.44641600  1.0
  O  O19  1  0.73528100  0.55890000  0.11166200  1.0
  O  O20  1  0.24284900  0.42490200  0.90023500  1.0
  O  O21  1  0.33094100  0.15372200  0.53634300  1.0
  O  O22  1  0.21446400  0.16489700  0.29810000  1.0
  O  O23  1  0.78653200  0.49645000  0.38030300  1.0
  F  F24  1  0.20721200  0.48774000  0.61109400  1.0
  F  F25  1  0.79872700  0.86103700  0.70833800  1.0
  F  F26  1  0.80553300  0.13882800  0.06602600  1.0
  F  F27  1  0.68064700  0.12128100  0.79255200  1.0

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