Li4Fe9CoO20
High-Entropy Materials HEAMP-ID: mp-765027 · Space group: P2/m (#10)
Basic Information
Formula
Li4Fe9CoO20
MP-ID
mp-765027
Elements
4
Sites
34
Density
4.1090
g/cm³
Volume
367.46
ų
Cell a
2.9331
Å
Cell b
5.9531
Å
Cell c
21.2502
Å
α Angle
82.03
°
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 |
|---|---|---|---|
| 18.24 | 4.8638 | 100.0 | (0,1,-2) |
| 35.38 | 2.5368 | 13.1 | (0,1,8) |
| 35.76 | 2.5108 | 23.3 | (1,1,3) |
| 36.96 | 2.4319 | 3.3 | (0,2,-4) |
| 37.02 | 2.4286 | 3.4 | (0,2,6) |
| 37.37 | 2.4064 | 6.0 | (1,0,5) |
| 42.98 | 2.1045 | 18.7 | (0,0,10) |
| 43.31 | 2.0892 | 36.2 | (1,2,1) |
| 47.07 | 1.9308 | 3.0 | (0,3,4) |
| 47.35 | 1.9199 | 6.6 | (1,1,-7) |
| 56.81 | 1.6207 | 4.4 | (0,1,-12) |
| 57.08 | 1.6135 | 9.1 | (1,3,-1) |
| 62.40 | 1.4883 | 3.9 | (0,4,2) |
| 62.62 | 1.4834 | 8.5 | (1,2,-9) |
| 62.69 | 1.4819 | 10.0 | (1,2,11) |
| 63.43 | 1.4665 | 5.3 | (2,0,0) |
| 65.88 | 1.4177 | 4.3 | (1,1,13) |
| 65.90 | 1.4175 | 4.7 | (1,3,9) |
| 66.60 | 1.4041 | 4.6 | (2,1,-2) |
| 73.87 | 1.2829 | 1.1 | (0,3,14) |
| 74.77 | 1.2696 | 2.5 | (2,1,8) |
| 75.01 | 1.2662 | 1.1 | (1,4,-3) |
| 75.05 | 1.2657 | 1.1 | (1,0,15) |
| 75.08 | 1.2653 | 1.2 | (1,4,7) |
Energy Properties
Formation Energy/atom
-1.51887
eV/atom
Energy/atom
-7.10589
eV/atom
Energy above Hull
0.1343
eV/atom
Uncorrected Energy
-6.0564
eV/atom
Volume/atom
10.81
ų
c/a Ratio
7.2450
Electronic Properties
Metallic
Metal
Band Gap
0
eV
Direct Gap
No
CBM
N/A
eV
Magnetic Properties
Magnetic
Yes
Total Mag. Moment
41.0000
μB
Mag. Ordering
FM
Mag. Sites
12
Magnetization/Volume
0.111580
μB/ų
Elastic Properties
Elastic data not available
Feature Analysis
Composition Overview
Element Composition (atomic fraction)
Composition Info
Major / Matrix Element
O · 0.588
Element Family
Metalloid-Nonmetal
Solute Fraction
0.412
Interstitial Fraction
0.000
High-Entropy Alloy Features
Composite Radar (normalized)
Element-Class Share
Mix Entropy ΔS/R
1.0195
HEA criterion (>1.0 = high entropy)
Mix Entropy ΔS
8.4757
J/mol·K
Ω Parameter
10.1940
Ω > 1.1 favors solid solution
Atomic Size Mismatch δr
40.893%
δr < 6.6% favors single-phase solid solution
Electronegativity Diff Δχ
0.9433
smaller = more stable mixing
VEC
4.853
valence electron concentration, affects phase stability
Mix Enthalpy ΔH_mix
0.513
kJ/mol; negative = exothermic mixing
Entropy Norm
0.7354
SS Former
0
Phase Tendency
IM
Related Tasks
Related computation task IDs (1)
Citation & References
Materials Project Page
https://materialsproject.org/materials/mp-765027
Reference Citation
The crystal structure and related material properties of Li4Fe9CoO20 were obtained from the Materials Project database (MP-ID: mp-765027, 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_Li4Fe9CoO20
_symmetry_space_group_name_H-M 'P 1'
_cell_length_a 2.93307700
_cell_length_b 5.95307600
_cell_length_c 21.25019833
_cell_angle_alpha 82.03065150
_cell_angle_beta 90.00000000
_cell_angle_gamma 90.00000000
_symmetry_Int_Tables_number 1
_chemical_formula_structural Li4Fe9CoO20
_chemical_formula_sum 'Li4 Fe9 Co1 O20'
_cell_volume 367.46268465
_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 0.70340600 0.60695000 1.0
Li Li1 1 0.50000000 0.29659400 0.39305000 1.0
Li Li2 1 0.00000000 0.69468500 0.09945700 1.0
Li Li3 1 0.00000000 0.30531500 0.90054300 1.0
Fe Fe4 1 0.50000000 0.62426400 0.79449200 1.0
Fe Fe5 1 0.00000000 0.36449700 0.70236700 1.0
Fe Fe6 1 0.50000000 0.20016900 0.59664800 1.0
Fe Fe7 1 0.00000000 0.00000000 0.50000000 1.0
Fe Fe8 1 0.50000000 0.79983100 0.40335200 1.0
Fe Fe9 1 0.00000000 0.63550300 0.29763300 1.0
Fe Fe10 1 0.50000000 0.37573600 0.20550800 1.0
Fe Fe11 1 0.00000000 0.20901400 0.09601600 1.0
Fe Fe12 1 0.00000000 0.79098600 0.90398400 1.0
Co Co13 1 0.50000000 0.00000000 0.00000000 1.0
O O14 1 0.50000000 0.57374900 0.89556000 1.0
O O15 1 0.00000000 0.82933600 0.80305100 1.0
O O16 1 0.00000000 0.39916500 0.79793000 1.0
O O17 1 0.50000000 0.15558700 0.68631500 1.0
O O18 1 0.50000000 0.59035600 0.69948400 1.0
O O19 1 0.00000000 0.97509900 0.59471300 1.0
O O20 1 0.00000000 0.41055800 0.60158500 1.0
O O21 1 0.50000000 0.22413600 0.50667000 1.0
O O22 1 0.50000000 0.77586400 0.49333000 1.0
O O23 1 0.00000000 0.02490100 0.40528700 1.0
O O24 1 0.00000000 0.58944200 0.39841500 1.0
O O25 1 0.50000000 0.84441300 0.31368500 1.0
O O26 1 0.50000000 0.40964400 0.30051600 1.0
O O27 1 0.00000000 0.17066400 0.19694900 1.0
O O28 1 0.00000000 0.60083500 0.20207000 1.0
O O29 1 0.50000000 0.97462500 0.08919300 1.0
O O30 1 0.50000000 0.42625100 0.10444000 1.0
O O31 1 0.00000000 0.20690500 0.99956100 1.0
O O32 1 0.00000000 0.79309500 0.00043900 1.0
O O33 1 0.50000000 0.02537500 0.91080700 1.0
