MgCo4O9

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-1041445 · Space group: Pc (#7)

Materials Project API

Basic Information

Formula

MgCo4O9

MP-ID

mp-1041445

Elements

Sites

Density

4.0981

g/cm³

Volume

327.43

Å³

Cell a

4.9015

Cell b

8.1590

Cell c

8.1875

α Angle

89.70

β Angle

90.00

γ Angle

90.00

Space Group

Point Group

Crystal System

Monoclinic

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
18.10	4.9015	100.0	(1,0,0)
21.12	4.2056	1.9	(1,0,-1)
21.13	4.2054	1.9	(1,0,1)
21.14	4.2017	2.0	(1,1,0)
21.15	4.2015	2.0	(1,-1,0)
21.71	4.0937	3.8	(0,0,2)
21.79	4.0795	3.6	(0,2,0)
23.78	3.7422	5.5	(1,-1,-1)
23.78	3.7422	5.5	(1,1,1)
23.83	3.7343	5.2	(1,1,-1)
23.83	3.7339	5.2	(1,-1,1)
28.41	3.1421	2.3	(1,0,-2)
28.41	3.1419	2.3	(1,0,2)
28.46	3.1357	2.5	(1,2,0)
28.47	3.1354	2.5	(1,-2,0)
30.45	2.9361	29.8	(1,-1,-2)
30.45	2.9359	29.8	(1,1,2)
30.57	2.9244	31.9	(1,2,-1)
30.57	2.9242	31.9	(1,-2,1)
30.86	2.8971	10.3	(0,2,2)
31.03	2.8822	10.4	(0,2,-2)
34.60	2.5922	9.6	(0,1,3)
34.70	2.5850	24.5	(0,3,1)
34.71	2.5842	24.6	(0,1,-3)

Get direct link

Energy Properties

Formation Energy/atom

-1.11657

eV/atom

Energy/atom

-6.45198

eV/atom

Energy above Hull

0.2608

eV/atom

Uncorrected Energy

-5.5423

eV/atom

Volume/atom

11.69

Å³

c/a Ratio

1.6704

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

24.0000

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.073300

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

O · 0.643

Element Family

Metalloid-Nonmetal

Solute Fraction

0.357

Interstitial Fraction

0.000

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

0.8305

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

6.9045

J/mol·K

Ω Parameter

1.7156

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

41.416%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.8136

smaller = more stable mixing

VEC

5.286

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-2.440

kJ/mol; negative = exothermic mixing

Entropy Norm

0.7559

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.456

Family

O-rich Multi-Component

Matrix Element

O · 0.643

Related Tasks

Related computation task IDs (2)

aaachgqe aaadyxfv

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-1041445

Reference Citation

The crystal structure and related material properties of MgCo4O9 were obtained from the Materials Project database (MP-ID: mp-1041445, 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_MgCo4O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.90151301
_cell_length_b   8.15901416
_cell_length_c   8.18754112
_cell_angle_alpha   89.70473221
_cell_angle_beta   90.00445676
_cell_angle_gamma   89.99586626
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgCo4O9
_chemical_formula_sum   'Mg2 Co8 O18'
_cell_volume   327.42781572
_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  0.14814500  0.24739800  0.24531700  1.0
  Mg  Mg1  1  0.85186600  0.74731700  0.74533400  1.0
  Co  Co2  1  0.61510900  0.53379000  0.33866400  1.0
  Co  Co3  1  0.38720800  0.83859700  0.46728300  1.0
  Co  Co4  1  0.61288000  0.33862500  0.96731200  1.0
  Co  Co5  1  0.38488900  0.03380400  0.83861300  1.0
  Co  Co6  1  0.61463800  0.96631000  0.16220900  1.0
  Co  Co7  1  0.61989800  0.16337700  0.53454700  1.0
  Co  Co8  1  0.38537000  0.46630100  0.66216100  1.0
  Co  Co9  1  0.37998900  0.66337200  0.03454300  1.0
  O  O10  1  0.49101000  0.74990700  0.25039200  1.0
  O  O11  1  0.50900500  0.24985000  0.75033300  1.0
  O  O12  1  0.05754900  0.68371300  0.97713600  1.0
  O  O13  1  0.06235400  0.52143500  0.68387900  1.0
  O  O14  1  0.06408700  0.97595800  0.81459300  1.0
  O  O15  1  0.06286500  0.81742200  0.52117600  1.0
  O  O16  1  0.93712400  0.31744800  0.02113300  1.0
  O  O17  1  0.93591400  0.47598000  0.31459500  1.0
  O  O18  1  0.93766400  0.02146100  0.18387200  1.0
  O  O19  1  0.94247900  0.18370700  0.47707800  1.0
  O  O20  1  0.44847900  0.04566700  0.35461300  1.0
  O  O21  1  0.42677500  0.14596200  0.04486400  1.0
  O  O22  1  0.43212600  0.35522800  0.45799100  1.0
  O  O23  1  0.43997300  0.45522500  0.14743900  1.0
  O  O24  1  0.55155900  0.54568400  0.85461700  1.0
  O  O25  1  0.56783600  0.85524600  0.95799400  1.0
  O  O26  1  0.57321800  0.64597700  0.54486900  1.0
  O  O27  1  0.55999700  0.95524200  0.64744000  1.0

Get direct link