Li2FeCo3O8

High-Entropy Materials HEA

MP-ID: mp-757856 · Space group: P6_3mc (#186)

Materials Project API

Basic Information

Formula

Li2FeCo3O8

MP-ID

mp-757856

Elements

Sites

Density

4.9514

g/cm³

Volume

251.21

Å³

Cell a

5.6493

Cell b

5.6493

Cell c

9.0887

α Angle

90.00

β Angle

90.00

γ Angle

120.00

Space Group

P6_3mc

Point Group

6mm

Crystal System

Hexagonal

Bravais Lattice

Stability

Packing Fraction

0.7405

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
19.53	4.5444	64.3	(0,0,0,2)
20.62	4.3080	100.0	(1,0,-1,1)
26.77	3.3296	29.3	(1,0,-1,2)
34.83	2.5757	35.9	(1,0,-1,3)
36.74	2.4462	15.6	(2,0,-2,0)
37.49	2.3990	49.6	(2,-1,-1,2)
38.10	2.3622	56.4	(2,0,-2,1)
39.67	2.2722	6.9	(0,0,0,4)
41.94	2.1540	35.7	(2,0,-2,2)
47.79	1.9033	56.1	(2,0,-2,3)
50.36	1.8121	5.7	(3,-1,-2,1)
51.63	1.7705	2.9	(2,-1,-1,4)
53.50	1.7128	12.6	(3,-1,-2,2)
55.17	1.6648	6.5	(2,-2,0,4)
55.17	1.6648	13.0	(2,0,-2,4)
58.47	1.5784	19.2	(3,-1,-2,3)
60.30	1.5350	11.7	(3,0,-3,2)
61.19	1.5148	2.3	(0,0,0,6)
63.79	1.4590	42.6	(2,0,-2,5)
66.17	1.4123	36.8	(4,-2,-2,0)
69.72	1.3487	6.2	(4,-2,-2,2)
69.72	1.3487	3.1	(2,2,-4,2)
70.12	1.3421	3.3	(4,-1,-3,1)
70.12	1.3421	1.6	(3,1,-4,1)

Get direct link

Energy Properties

Formation Energy/atom

-1.48104

eV/atom

Energy/atom

-6.71474

eV/atom

Energy above Hull

0.0824

eV/atom

Uncorrected Energy

-5.8100

eV/atom

Volume/atom

8.97

Å³

c/a Ratio

1.6088

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

6.0000

μB

Mag. Ordering

FiM

Mag. Sites

Magnetization/Volume

0.023880

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

1.1164

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

9.2815

J/mol·K

Ω Parameter

0.9573

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

40.987%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.9644

smaller = more stable mixing

VEC

4.929

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-5.860

kJ/mol; negative = exothermic mixing

Entropy Norm

0.8053

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (1)

aaaegisc

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-757856

Reference Citation

The crystal structure and related material properties of Li2FeCo3O8 were obtained from the Materials Project database (MP-ID: mp-757856, 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_Li2FeCo3O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.64933644
_cell_length_b   5.64933644
_cell_length_c   9.08872400
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   120.00000517
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Li2FeCo3O8
_chemical_formula_sum   'Li4 Fe2 Co6 O16'
_cell_volume   251.20507175
_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  0.33333300  0.66666700  0.89422600  1.0
  Li  Li1  1  0.00000000  0.00000000  0.99788000  1.0
  Li  Li2  1  0.00000000  0.00000000  0.49788000  1.0
  Li  Li3  1  0.66666700  0.33333300  0.39422600  1.0
  Fe  Fe4  1  0.33333300  0.66666700  0.49007400  1.0
  Fe  Fe5  1  0.66666700  0.33333300  0.99007400  1.0
  Co  Co6  1  0.17086400  0.82913600  0.21265700  1.0
  Co  Co7  1  0.17086400  0.34172800  0.21265700  1.0
  Co  Co8  1  0.65827200  0.82913600  0.21265700  1.0
  Co  Co9  1  0.34172800  0.17086400  0.71265700  1.0
  Co  Co10  1  0.82913600  0.65827200  0.71265700  1.0
  Co  Co11  1  0.82913600  0.17086400  0.71265700  1.0
  O  O12  1  0.16786100  0.83213900  0.59934100  1.0
  O  O13  1  0.04390900  0.52195400  0.34110900  1.0
  O  O14  1  0.33333300  0.66666700  0.10722900  1.0
  O  O15  1  0.00000000  0.00000000  0.30551500  1.0
  O  O16  1  0.00000000  0.00000000  0.80551500  1.0
  O  O17  1  0.16786100  0.33572100  0.59934100  1.0
  O  O18  1  0.47804600  0.95609100  0.34110900  1.0
  O  O19  1  0.47804600  0.52195400  0.34110900  1.0
  O  O20  1  0.33572100  0.16786100  0.09934100  1.0
  O  O21  1  0.66427900  0.83213900  0.59934100  1.0
  O  O22  1  0.52195400  0.47804600  0.84110900  1.0
  O  O23  1  0.52195400  0.04390900  0.84110900  1.0
  O  O24  1  0.66666700  0.33333300  0.60722900  1.0
  O  O25  1  0.83213900  0.66427900  0.09934100  1.0
  O  O26  1  0.95609100  0.47804600  0.84110900  1.0
  O  O27  1  0.83213900  0.16786100  0.09934100  1.0

Get direct link