Mg(CoO2)2

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-1048911 · Space group: R3m (#160)

Materials Project API

Basic Information

Formula

Mg(CoO2)2

MP-ID

mp-1048911

Elements

Sites

Density

4.5707

g/cm³

Volume

149.80

Å³

Cell a

5.9724

Cell b

5.9724

Cell c

5.9724

α Angle

59.76

β Angle

59.76

γ Angle

59.76

Space Group

R3m

Point Group

Crystal System

Trigonal

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
18.16	4.8855	62.1	(1,1,1)
18.25	4.8614	19.3	(1,0,0)
21.08	4.2153	21.6	(1,1,0)
29.92	2.9862	52.4	(2,1,1)
30.04	2.9752	9.3	(1,0,-1)
35.22	2.5479	45.6	(2,2,1)
35.32	2.5411	92.1	(2,1,0)
35.37	2.5377	100.0	(1,1,-1)
36.79	2.4427	4.3	(2,2,2)
36.98	2.4307	11.0	(2,0,0)
36.98	2.4307	5.5	(0,0,2)
42.91	2.1077	23.8	(2,2,0)
42.91	2.1077	47.6	(2,0,2)
46.84	1.9398	1.8	(3,2,2)
46.95	1.9352	2.6	(3,1,1)
46.95	1.9352	1.3	(1,1,3)
47.07	1.9307	1.2	(2,0,-1)
48.20	1.8879	4.2	(3,2,1)
48.20	1.8879	2.1	(2,1,3)
48.35	1.8824	3.0	(2,1,-1)
53.05	1.7262	1.2	(3,2,3)
53.26	1.7198	11.3	(3,1,0)
53.26	1.7198	5.7	(1,0,3)
53.33	1.7177	1.6	(2,-1,-1)

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Energy Properties

Formation Energy/atom

-1.71980

eV/atom

Energy/atom

-6.81825

eV/atom

Energy above Hull

0.1156

eV/atom

Uncorrected Energy

-5.9577

eV/atom

Volume/atom

10.70

Å³

c/a Ratio

1.0000

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

3.9998

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.026700

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

0.9557

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

7.9457

J/mol·K

Ω Parameter

1.0881

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

42.482%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.8837

smaller = more stable mixing

VEC

5.143

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-4.880

kJ/mol; negative = exothermic mixing

Entropy Norm

0.8699

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.485

Family

O-rich Multi-Component

Matrix Element

O · 0.571

Related Tasks

Related computation task IDs (2)

aaachrri aaaefnxd

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-1048911

Reference Citation

The crystal structure and related material properties of Mg(CoO2)2 were obtained from the Materials Project database (MP-ID: mp-1048911, 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…

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Raw CIF Data

# generated using pymatgen
data_Mg(CoO2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.97244258
_cell_length_b   5.97244258
_cell_length_c   5.97244163
_cell_angle_alpha   59.75553180
_cell_angle_beta   59.75553180
_cell_angle_gamma   59.75553152
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Mg(CoO2)2
_chemical_formula_sum   'Mg2 Co4 O8'
_cell_volume   149.80397049
_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
  Mg  Mg0  1  0.00409700  0.00409700  0.00409700  1.0
  Mg  Mg1  1  0.62535600  0.62535600  0.62535600  1.0
  Co  Co2  1  0.24572900  0.24572900  0.24572900  1.0
  Co  Co3  1  0.62622600  0.12085400  0.62622600  1.0
  Co  Co4  1  0.62622600  0.62622600  0.12085400  1.0
  Co  Co5  1  0.12085400  0.62622600  0.62622600  1.0
  O  O6  1  0.84400400  0.37838000  0.37838000  1.0
  O  O7  1  0.37838000  0.37838000  0.84400400  1.0
  O  O8  1  0.37838000  0.84400400  0.37838000  1.0
  O  O9  1  0.38128900  0.38128900  0.38128900  1.0
  O  O10  1  0.86798300  0.86798300  0.86798300  1.0
  O  O11  1  0.87098900  0.40949700  0.87098900  1.0
  O  O12  1  0.87098900  0.87098900  0.40949700  1.0
  O  O13  1  0.40949700  0.87098900  0.87098900  1.0

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