Na(CoO2)8

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-675264 · Space group: P-1 (#2)

Materials Project API

Basic Information

Formula

Na(CoO2)8

MP-ID

mp-675264

Elements

Sites

Density

4.4409

g/cm³

Volume

561.22

Å³

Cell a

6.7111

Cell b

7.1768

Cell c

12.2199

α Angle

78.08

β Angle

86.96

γ Angle

77.05

Space Group

P-1

Point Group

-1

Crystal System

Triclinic

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
7.39	11.9560	61.2	(0,0,1)
12.92	6.8530	4.7	(0,1,0)
13.54	6.5404	26.0	(1,0,0)
13.55	6.5365	18.4	(0,1,1)
14.82	5.9780	30.6	(0,0,2)
15.40	5.7553	1.3	(1,0,1)
15.49	5.7207	9.6	(1,0,-1)
17.03	5.2080	11.7	(1,1,1)
19.24	4.6125	4.6	(1,1,-1)
20.20	4.3969	3.6	(1,0,-2)
21.59	4.1155	66.9	(0,1,-2)
22.86	3.8897	6.9	(1,-1,1)
24.04	3.7016	1.3	(1,-1,-2)
24.05	3.6998	2.1	(1,1,-2)
25.57	3.4836	1.5	(0,2,1)
25.62	3.4773	4.4	(1,1,3)
26.00	3.4265	11.3	(0,2,0)
26.10	3.4142	11.0	(1,0,3)
26.61	3.3503	5.2	(1,2,0)
27.27	3.2702	2.3	(2,0,0)
27.29	3.2682	14.3	(0,2,2)
27.54	3.2386	22.8	(2,1,0)
27.80	3.2094	33.0	(2,1,1)
27.81	3.2080	3.3	(1,2,2)

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Energy Properties

Formation Energy/atom

-0.58655

eV/atom

Energy/atom

-6.08960

eV/atom

Energy above Hull

0.6025

eV/atom

Uncorrected Energy

-5.4624

eV/atom

Volume/atom

11.22

Å³

c/a Ratio

1.8209

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

34.0000

μB

Mag. Ordering

FiM

Mag. Sites

Magnetization/Volume

0.060580

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

O · 0.640

Element Family

Metalloid-Nonmetal

Solute Fraction

0.360

Interstitial Fraction

0.000

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

0.7790

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

6.4766

J/mol·K

Ω Parameter

4.9725

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

42.314%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.8193

smaller = more stable mixing

VEC

5.480

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-0.802

kJ/mol; negative = exothermic mixing

Entropy Norm

0.7091

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.437

Family

O-rich Multi-Component

Matrix Element

O · 0.640

Related Tasks

Related computation task IDs (1)

aaaedesu

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-675264

Reference Citation

The crystal structure and related material properties of Na(CoO2)8 were obtained from the Materials Project database (MP-ID: mp-675264, 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_Na(CoO2)8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.71111300
_cell_length_b   7.17682206
_cell_length_c   12.21993193
_cell_angle_alpha   78.07713912
_cell_angle_beta   86.95534268
_cell_angle_gamma   77.05435501
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na(CoO2)8
_chemical_formula_sum   'Na2 Co16 O32'
_cell_volume   561.21785816
_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  0.61707900  0.14795600  0.09093600  1.0
  Na  Na1  1  0.38292100  0.85204400  0.90906400  1.0
  Co  Co2  1  0.87346400  0.28126500  0.86405500  1.0
  Co  Co3  1  0.79201700  0.73311600  0.63274700  1.0
  Co  Co4  1  0.64989200  0.13010100  0.70407700  1.0
  Co  Co5  1  0.50000000  0.50000000  0.50000000  1.0
  Co  Co6  1  0.28547700  0.35443700  0.81640900  1.0
  Co  Co7  1  0.29685900  0.67718800  0.64044500  1.0
  Co  Co8  1  0.35010800  0.86989900  0.29592300  1.0
  Co  Co9  1  0.20798300  0.26688400  0.36725300  1.0
  Co  Co10  1  0.11033100  0.09633600  0.68112300  1.0
  Co  Co11  1  0.00000000  0.50000000  0.50000000  1.0
  Co  Co12  1  0.05992500  0.25141600  0.12181100  1.0
  Co  Co13  1  0.12653600  0.71873500  0.13594500  1.0
  Co  Co14  1  0.88966900  0.90366400  0.31887700  1.0
  Co  Co15  1  0.70314100  0.32281200  0.35955500  1.0
  Co  Co16  1  0.71452300  0.64556300  0.18359100  1.0
  Co  Co17  1  0.94007500  0.74858400  0.87818900  1.0
  O  O18  1  0.48353300  0.21330400  0.31843600  1.0
  O  O19  1  0.34834900  0.90065300  0.12205400  1.0
  O  O20  1  0.84805100  0.26607800  0.71119500  1.0
  O  O21  1  0.56317800  0.52299800  0.10887300  1.0
  O  O22  1  0.63418300  0.48791900  0.86915100  1.0
  O  O23  1  0.43860100  0.98373900  0.70208300  1.0
  O  O24  1  0.30367900  0.10087600  0.06984300  1.0
  O  O25  1  0.56237000  0.62346300  0.32482200  1.0
  O  O26  1  0.43763000  0.37653700  0.67517800  1.0
  O  O27  1  0.69632100  0.89912400  0.93015700  1.0
  O  O28  1  0.56139900  0.01626100  0.29791700  1.0
  O  O29  1  0.94355000  0.40693000  0.37977500  1.0
  O  O30  1  0.15194900  0.73392200  0.28880500  1.0
  O  O31  1  0.36581700  0.51208100  0.13084900  1.0
  O  O32  1  0.43682200  0.47700200  0.89112700  1.0
  O  O33  1  0.65165100  0.09934700  0.87794600  1.0
  O  O34  1  0.24458800  0.87087700  0.49834700  1.0
  O  O35  1  0.84704300  0.85391000  0.17053100  1.0
  O  O36  1  0.73242100  0.57895800  0.53843100  1.0
  O  O37  1  0.11879600  0.10727100  0.27865100  1.0
  O  O38  1  0.90403500  0.22005700  0.01951100  1.0
  O  O39  1  0.51646700  0.78669600  0.68156400  1.0
  O  O40  1  0.98031200  0.49896600  0.14487500  1.0
  O  O41  1  0.81111800  0.94060300  0.47778200  1.0
  O  O42  1  0.01968800  0.50103400  0.85512500  1.0
  O  O43  1  0.18888200  0.05939700  0.52221800  1.0
  O  O44  1  0.09596500  0.77994300  0.98048900  1.0
  O  O45  1  0.88120400  0.89272900  0.72134900  1.0
  O  O46  1  0.26757900  0.42104200  0.46156900  1.0
  O  O47  1  0.15295700  0.14609000  0.82946900  1.0
  O  O48  1  0.75541200  0.12912300  0.50165300  1.0
  O  O49  1  0.05645000  0.59307000  0.62022500  1.0

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