Li8Fe9CoO20
High-Entropy Materials HEAMP-ID: mp-759442 · Space group: P2/m (#10)
Basic Information
Formula
Li8Fe9CoO20
MP-ID
mp-759442
Elements
4
Sites
38
Density
4.1665
g/cm³
Volume
373.46
ų
Cell a
2.9562
Å
Cell b
5.9684
Å
Cell c
21.3588
Å
α Angle
82.31
°
β Angle
90.00
°
γ Angle
90.00
°
Space Group
P2/m
Point Group
2/m
Crystal System
Monoclinic
Bravais Lattice
mP
Stability
No
Packing Fraction
-
X-ray Diffraction
Diffraction Pattern
X-axis: 2θ (°); Y-axis: relative intensity; Cu Kα ; λ=1.5418 Å
Diffraction Peaks (Top 24)
| 2θ | d (Å) | I | hkl |
|---|---|---|---|
| 18.13 | 4.8918 | 100.0 | (0,1,-2) |
| 35.26 | 2.5455 | 13.7 | (0,1,8) |
| 35.54 | 2.5263 | 27.1 | (1,1,3) |
| 36.74 | 2.4459 | 4.4 | (0,2,-4) |
| 36.96 | 2.4323 | 4.1 | (0,2,6) |
| 37.09 | 2.4237 | 7.9 | (1,0,5) |
| 42.72 | 2.1167 | 23.8 | (0,0,10) |
| 43.07 | 2.1002 | 47.1 | (1,2,1) |
| 46.98 | 1.9342 | 4.5 | (0,3,4) |
| 46.98 | 1.9340 | 8.6 | (1,1,-7) |
| 56.39 | 1.6316 | 4.7 | (0,1,-12) |
| 56.43 | 1.6306 | 1.8 | (0,3,-6) |
| 56.78 | 1.6215 | 9.4 | (1,3,-1) |
| 62.13 | 1.4939 | 12.3 | (1,2,-9) |
| 62.22 | 1.4921 | 6.1 | (0,4,2) |
| 62.42 | 1.4877 | 13.1 | (1,2,11) |
| 62.87 | 1.4781 | 6.6 | (2,0,0) |
| 65.50 | 1.4251 | 4.8 | (1,1,13) |
| 65.67 | 1.4217 | 4.8 | (1,3,9) |
| 66.03 | 1.4149 | 4.7 | (2,1,-2) |
| 73.68 | 1.2857 | 1.4 | (0,3,14) |
| 74.19 | 1.2782 | 2.6 | (2,1,8) |
| 74.51 | 1.2735 | 1.4 | (1,0,15) |
| 74.58 | 1.2725 | 1.5 | (1,4,-3) |
Energy Properties
Formation Energy/atom
-1.81705
eV/atom
Energy/atom
-7.01690
eV/atom
Energy above Hull
0.0294
eV/atom
Uncorrected Energy
-6.0779
eV/atom
Volume/atom
9.83
ų
c/a Ratio
7.2252
Electronic Properties
Metallic
Metal
Band Gap
0
eV
Direct Gap
No
CBM
N/A
eV
Magnetic Properties
Magnetic
Yes
Total Mag. Moment
44.9993
μB
Mag. Ordering
FM
Mag. Sites
24
Magnetization/Volume
0.120490
μB/ų
Elastic Properties
Elastic data not available
Feature Analysis
Composition Overview
Element Composition (atomic fraction)
Composition Info
Major / Matrix Element
O · 0.526
Element Family
Metalloid-Nonmetal
Solute Fraction
0.474
Interstitial Fraction
0.000
High-Entropy Alloy Features
Composite Radar (normalized)
Element-Class Share
Mix Entropy ΔS/R
1.1027
HEA criterion (>1.0 = high entropy)
Mix Entropy ΔS
9.1680
J/mol·K
Ω Parameter
6.4977
Ω > 1.1 favors solid solution
Atomic Size Mismatch δr
41.063%
δr < 6.6% favors single-phase solid solution
Electronegativity Diff Δχ
1.0334
smaller = more stable mixing
VEC
4.447
valence electron concentration, affects phase stability
Mix Enthalpy ΔH_mix
0.846
kJ/mol; negative = exothermic mixing
Entropy Norm
0.7954
SS Former
0
Phase Tendency
IM
Related Tasks
Related computation task IDs (1)
Citation & References
Materials Project Page
https://materialsproject.org/materials/mp-759442
Reference Citation
The crystal structure and related material properties of Li8Fe9CoO20 were obtained from the Materials Project database (MP-ID: mp-759442, 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_Li8Fe9CoO20
_symmetry_space_group_name_H-M 'P 1'
_cell_length_a 2.95617100
_cell_length_b 5.96841900
_cell_length_c 21.35881339
_cell_angle_alpha 82.30724624
_cell_angle_beta 90.00000000
_cell_angle_gamma 90.00000000
_symmetry_Int_Tables_number 1
_chemical_formula_structural Li8Fe9CoO20
_chemical_formula_sum 'Li8 Fe9 Co1 O20'
_cell_volume 373.45621602
_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
Li Li0 1 0.50000000 0.09919800 0.79912600 1.0
Li Li1 1 0.00000000 0.90126400 0.69854500 1.0
Li Li2 1 0.50000000 0.69626000 0.59755700 1.0
Li Li3 1 0.50000000 0.30374000 0.40244300 1.0
Li Li4 1 0.00000000 0.09873600 0.30145500 1.0
Li Li5 1 0.50000000 0.90080200 0.20087400 1.0
Li Li6 1 0.00000000 0.69744800 0.09510800 1.0
Li Li7 1 0.00000000 0.30255200 0.90489200 1.0
Fe Fe8 1 0.50000000 0.60262100 0.80090200 1.0
Fe Fe9 1 0.00000000 0.39971700 0.70121400 1.0
Fe Fe10 1 0.50000000 0.21022000 0.59864900 1.0
Fe Fe11 1 0.00000000 0.00000000 0.50000000 1.0
Fe Fe12 1 0.50000000 0.78978000 0.40135100 1.0
Fe Fe13 1 0.00000000 0.60028300 0.29878600 1.0
Fe Fe14 1 0.50000000 0.39737900 0.19909800 1.0
Fe Fe15 1 0.00000000 0.21475500 0.09518200 1.0
Fe Fe16 1 0.00000000 0.78524500 0.90481800 1.0
Co Co17 1 0.50000000 0.00000000 0.00000000 1.0
O O18 1 0.50000000 0.56272400 0.89675000 1.0
O O19 1 0.00000000 0.83878300 0.80589400 1.0
O O20 1 0.00000000 0.36322600 0.79836800 1.0
O O21 1 0.50000000 0.16396100 0.69774900 1.0
O O22 1 0.50000000 0.63734900 0.70409000 1.0
O O23 1 0.00000000 0.97069400 0.59751400 1.0
O O24 1 0.00000000 0.43753800 0.60563100 1.0
O O25 1 0.50000000 0.21590600 0.50161200 1.0
O O26 1 0.50000000 0.78409400 0.49838800 1.0
O O27 1 0.00000000 0.02930600 0.40248600 1.0
O O28 1 0.00000000 0.56246200 0.39436900 1.0
O O29 1 0.50000000 0.83603900 0.30225100 1.0
O O30 1 0.50000000 0.36265100 0.29591000 1.0
O O31 1 0.00000000 0.16121700 0.19410600 1.0
O O32 1 0.00000000 0.63677400 0.20163200 1.0
O O33 1 0.50000000 0.97337000 0.09001000 1.0
O O34 1 0.50000000 0.43727600 0.10325000 1.0
O O35 1 0.00000000 0.20538800 0.00034900 1.0
O O36 1 0.00000000 0.79461200 0.99965100 1.0
O O37 1 0.50000000 0.02663000 0.90999000 1.0
