Li6Fe9CoO20
High-Entropy Materials HEAMP-ID: mp-765392 · Space group: Pm (#6)
Basic Information
Formula
Li6Fe9CoO20
MP-ID
mp-765392
Elements
4
Sites
36
Density
4.0809
g/cm³
Volume
375.65
ų
Cell a
2.9655
Å
Cell b
6.0423
Å
Cell c
21.1325
Å
α Angle
82.77
°
β Angle
90.00
°
γ Angle
90.00
°
Space Group
Pm
Point Group
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 |
|---|---|---|---|
| 17.95 | 4.9422 | 100.0 | (0,1,-2) |
| 35.46 | 2.5318 | 24.4 | (1,1,3) |
| 35.62 | 2.5204 | 11.9 | (0,1,8) |
| 36.36 | 2.4711 | 4.0 | (0,2,-4) |
| 36.97 | 2.4312 | 3.5 | (0,2,6) |
| 37.13 | 2.4211 | 6.6 | (1,0,5) |
| 42.73 | 2.1162 | 40.8 | (1,2,1) |
| 43.15 | 2.0964 | 19.4 | (0,0,10) |
| 46.56 | 1.9506 | 3.7 | (0,3,4) |
| 46.96 | 1.9351 | 6.9 | (1,1,-7) |
| 55.80 | 1.6474 | 1.3 | (0,3,-6) |
| 56.13 | 1.6385 | 9.8 | (1,3,-1) |
| 56.71 | 1.6232 | 4.7 | (0,1,-12) |
| 61.38 | 1.5104 | 5.1 | (0,4,2) |
| 61.93 | 1.4984 | 10.0 | (1,2,-9) |
| 62.65 | 1.4828 | 5.7 | (2,0,0) |
| 62.76 | 1.4805 | 10.8 | (1,2,11) |
| 65.65 | 1.4222 | 4.6 | (1,3,9) |
| 65.75 | 1.4202 | 4.6 | (2,1,-2) |
| 66.07 | 1.4142 | 4.5 | (1,1,13) |
| 73.58 | 1.2872 | 1.5 | (1,4,-3) |
| 74.20 | 1.2780 | 2.4 | (2,1,8) |
| 74.20 | 1.2780 | 1.2 | (0,3,14) |
| 74.35 | 1.2758 | 1.3 | (1,4,7) |
Energy Properties
Formation Energy/atom
-1.68623
eV/atom
Energy/atom
-7.06890
eV/atom
Energy above Hull
0.0690
eV/atom
Uncorrected Energy
-6.0777
eV/atom
Volume/atom
10.43
ų
c/a Ratio
7.1261
Electronic Properties
Metallic
Metal
Band Gap
0
eV
Direct Gap
No
CBM
N/A
eV
Magnetic Properties
Magnetic
Yes
Total Mag. Moment
43.0014
μB
Mag. Ordering
FM
Mag. Sites
14
Magnetization/Volume
0.114470
μB/ų
Elastic Properties
Elastic data not available
Feature Analysis
Composition Overview
Element Composition (atomic fraction)
Composition Info
Major / Matrix Element
O · 0.556
Element Family
Metalloid-Nonmetal
Solute Fraction
0.444
Interstitial Fraction
0.000
High-Entropy Alloy Features
Composite Radar (normalized)
Element-Class Share
Mix Entropy ΔS/R
1.0713
HEA criterion (>1.0 = high entropy)
Mix Entropy ΔS
8.9067
J/mol·K
Ω Parameter
7.7323
Ω > 1.1 favors solid solution
Atomic Size Mismatch δr
41.160%
δr < 6.6% favors single-phase solid solution
Electronegativity Diff Δχ
0.9959
smaller = more stable mixing
VEC
4.639
valence electron concentration, affects phase stability
Mix Enthalpy ΔH_mix
0.700
kJ/mol; negative = exothermic mixing
Entropy Norm
0.7728
SS Former
0
Phase Tendency
IM
Related Tasks
Related computation task IDs (1)
Citation & References
Materials Project Page
https://materialsproject.org/materials/mp-765392
Reference Citation
The crystal structure and related material properties of Li6Fe9CoO20 were obtained from the Materials Project database (MP-ID: mp-765392, 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…
Style: Ball & Stick
|
Drag to rotate · Scroll to zoom · Right-click to pan
Raw CIF Data
# generated using pymatgen
data_Li6Fe9CoO20
_symmetry_space_group_name_H-M 'P 1'
_cell_length_a 2.96550200
_cell_length_b 6.04231500
_cell_length_c 21.13245461
_cell_angle_alpha 82.76517126
_cell_angle_beta 90.00000000
_cell_angle_gamma 90.00000000
_symmetry_Int_Tables_number 1
_chemical_formula_structural Li6Fe9CoO20
_chemical_formula_sum 'Li6 Fe9 Co1 O20'
_cell_volume 375.64704895
_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 0.00000000 0.60650200 0.80668400 1.0
Li Li1 1 0.50000000 0.38063900 0.69305000 1.0
Li Li2 1 0.50000000 0.00353000 0.49964500 1.0
Li Li3 1 0.50000000 0.60966000 0.30628400 1.0
Li Li4 1 0.00000000 0.38884400 0.19266400 1.0
Li Li5 1 0.00000000 0.99966500 0.00066800 1.0
Fe Fe6 1 0.50000000 0.30142800 0.90032500 1.0
Fe Fe7 1 0.00000000 0.08199600 0.80527000 1.0
Fe Fe8 1 0.50000000 0.91386000 0.69782700 1.0
Fe Fe9 1 0.00000000 0.70232000 0.60043300 1.0
Fe Fe10 1 0.50000000 0.49931900 0.50043400 1.0
Fe Fe11 1 0.00000000 0.30173000 0.39959200 1.0
Fe Fe12 1 0.50000000 0.08493300 0.30228200 1.0
Fe Fe13 1 0.00000000 0.91229200 0.19540200 1.0
Fe Fe14 1 0.00000000 0.50309000 0.99985500 1.0
Co Co15 1 0.50000000 0.70002900 0.09930700 1.0
O O16 1 0.50000000 0.27294500 0.99128300 1.0
O O17 1 0.00000000 0.50935800 0.90274800 1.0
O O18 1 0.00000000 0.09325200 0.90025500 1.0
O O19 1 0.50000000 0.86023400 0.79532500 1.0
O O20 1 0.50000000 0.32529200 0.80974000 1.0
O O21 1 0.00000000 0.67258900 0.69351900 1.0
O O22 1 0.00000000 0.13610900 0.70784300 1.0
O O23 1 0.50000000 0.92014700 0.60141700 1.0
O O24 1 0.50000000 0.48427200 0.59748700 1.0
O O25 1 0.00000000 0.73083400 0.50781900 1.0
O O26 1 0.00000000 0.27330500 0.49414700 1.0
O O27 1 0.50000000 0.51927900 0.40328700 1.0
O O28 1 0.50000000 0.08478200 0.39880100 1.0
O O29 1 0.00000000 0.86157100 0.29270800 1.0
O O30 1 0.00000000 0.32764300 0.30497200 1.0
O O31 1 0.50000000 0.67566400 0.18893900 1.0
O O32 1 0.50000000 0.13569500 0.20445400 1.0
O O33 1 0.00000000 0.90209100 0.09966100 1.0
O O34 1 0.00000000 0.49746000 0.09692200 1.0
O O35 1 0.50000000 0.72738600 0.00930000 1.0
