Na3(CoO2)4

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-766225 · Space group: Pmmn (#59)

Materials Project API

Basic Information

Formula

Na3(CoO2)4

MP-ID

mp-766225

Elements

Sites

Density

4.8530

g/cm³

Volume

296.11

Å³

Cell a

2.8460

Cell b

9.7165

Cell c

10.7079

α Angle

90.00

β Angle

90.00

γ Angle

90.00

Space Group

Pmmn

Point Group

mmm

Crystal System

Orthorhombic

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
16.56	5.3540	100.0	(0,0,2)
27.54	3.2388	1.9	(0,3,0)
32.30	2.7712	3.1	(0,3,2)
33.47	2.6770	16.7	(0,0,4)
33.87	2.6465	2.4	(1,1,1)
36.59	2.4557	17.1	(1,2,0)
37.01	2.4291	7.3	(0,4,0)
40.41	2.2321	33.5	(1,2,2)
40.79	2.2121	18.6	(0,4,2)
41.64	2.1691	2.4	(1,1,3)
43.88	2.0634	1.5	(0,3,4)
44.80	2.0231	12.6	(1,2,3)
45.15	2.0082	3.9	(0,4,3)
50.43	1.8096	31.2	(1,2,4)
50.75	1.7989	13.7	(0,4,4)
64.55	1.4437	13.7	(1,2,6)
64.83	1.4382	7.3	(0,4,6)
65.61	1.4230	7.0	(2,0,0)
66.42	1.4075	11.8	(1,6,0)
68.19	1.3753	3.3	(2,0,2)
68.99	1.3613	7.9	(1,6,2)
70.33	1.3385	2.8	(0,0,8)
75.69	1.2565	3.1	(2,0,4)
76.46	1.2458	4.8	(1,6,4)

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Energy Properties

Formation Energy/atom

-1.50214

eV/atom

Energy/atom

-6.31164

eV/atom

Energy above Hull

0.0016

eV/atom

Uncorrected Energy

-8.9752

eV/atom

Volume/atom

9.87

Å³

c/a Ratio

3.7624

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

1.9666

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.006640

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

O · 0.533

Element Family

Metalloid-Nonmetal

Solute Fraction

0.467

Interstitial Fraction

0.000

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

1.0096

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

8.3939

J/mol·K

Ω Parameter

1.4443

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

48.694%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

1.0326

smaller = more stable mixing

VEC

4.733

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-3.341

kJ/mol; negative = exothermic mixing

Entropy Norm

0.9190

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.495

Family

O-rich Multi-Component

Matrix Element

O · 0.533

Related Tasks

Related computation task IDs (2)

aaabzfes aaagazto

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-766225

Reference Citation

The crystal structure and related material properties of Na3(CoO2)4 were obtained from the Materials Project database (MP-ID: mp-766225, 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_Na3(CoO2)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.84600617
_cell_length_b   9.71648758
_cell_length_c   10.70792661
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   90.00000000
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na3(CoO2)4
_chemical_formula_sum   'Na6 Co8 O16'
_cell_volume   296.10826056
_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
  Na  Na0  1  0.00000000  0.35566486  0.50000000  1.0
  Na  Na1  1  0.00000000  0.69605452  0.50000000  1.0
  Na  Na2  1  -0.00000000  0.00669504  0.00000000  1.0
  Na  Na3  1  0.50000000  0.64433514  0.00000000  1.0
  Na  Na4  1  0.50000000  0.99330496  0.50000000  1.0
  Na  Na5  1  0.50000000  0.30394548  0.00000000  1.0
  Co  Co6  1  0.00000000  0.87423068  0.74716678  1.0
  Co  Co7  1  -0.00000000  0.87423068  0.25283322  1.0
  Co  Co8  1  0.00000000  0.37622171  0.75499383  1.0
  Co  Co9  1  -0.00000000  0.37622171  0.24500617  1.0
  Co  Co10  1  0.50000000  0.62377829  0.74500617  1.0
  Co  Co11  1  0.50000000  0.62377829  0.25499383  1.0
  Co  Co12  1  0.50000000  0.12576932  0.24716678  1.0
  Co  Co13  1  0.50000000  0.12576932  0.75283322  1.0
  O  O14  1  0.00000000  0.70710794  0.83522386  1.0
  O  O15  1  -0.00000000  0.20664567  0.84819351  1.0
  O  O16  1  -0.00000000  0.70710794  0.16477614  1.0
  O  O17  1  -0.00000000  0.53755895  0.65715123  1.0
  O  O18  1  -0.00000000  0.20664567  0.15180649  1.0
  O  O19  1  0.00000000  0.04493337  0.66103467  1.0
  O  O20  1  -0.00000000  0.53755895  0.34284877  1.0
  O  O21  1  0.00000000  0.04493337  0.33896533  1.0
  O  O22  1  0.50000000  0.46244105  0.84284877  1.0
  O  O23  1  0.50000000  0.95506663  0.83896533  1.0
  O  O24  1  0.50000000  0.79335433  0.65180649  1.0
  O  O25  1  0.50000000  0.29289206  0.66477614  1.0
  O  O26  1  0.50000000  0.95506663  0.16103467  1.0
  O  O27  1  0.50000000  0.79335433  0.34819351  1.0
  O  O28  1  0.50000000  0.46244105  0.15715123  1.0
  O  O29  1  0.50000000  0.29289206  0.33522386  1.0

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