NbCo3O8

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-757799 · Space group: P6_3mc (#186)

Materials Project API

Basic Information

Formula

NbCo3O8

MP-ID

mp-757799

Elements

Sites

Density

5.1080

g/cm³

Volume

258.57

Å³

Cell a

5.6894

Cell b

5.6894

Cell c

9.2278

α Angle

89.91

β Angle

89.91

γ Angle

120.04

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
18.00	4.9281	2.2	(1,-1,0,0)
18.01	4.9252	4.4	(1,0,-1,0)
19.24	4.6139	100.0	(0,0,0,2)
20.42	4.3497	92.9	(1,0,-1,1)
20.43	4.3470	93.2	(1,-1,0,1)
20.46	4.3404	93.6	(1,0,-1,-1)
26.44	3.3715	30.2	(1,0,-1,2)
26.46	3.3681	30.5	(1,-1,0,2)
26.51	3.3628	30.3	(1,0,-1,-2)
31.45	2.8447	4.0	(2,-1,-1,0)
31.47	2.8430	2.0	(1,1,-2,0)
34.33	2.6120	36.7	(1,0,-1,3)
34.37	2.6094	36.5	(1,-1,0,3)
34.42	2.6059	36.1	(1,0,-1,-3)
36.46	2.4641	13.0	(2,-2,0,0)
36.49	2.4626	26.2	(2,0,-2,0)
37.09	2.4236	22.1	(1,1,-2,2)
37.10	2.4231	44.4	(2,-1,-1,2)
37.15	2.4198	44.5	(2,-1,-1,-2)
37.20	2.4172	22.1	(1,1,-2,-2)
37.79	2.3809	39.8	(2,0,-2,1)
37.79	2.3806	39.3	(2,-2,0,1)
37.84	2.3778	38.8	(2,0,-2,-1)
39.04	2.3069	20.5	(0,0,0,4)

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Energy Properties

Formation Energy/atom

-1.57961

eV/atom

Energy/atom

-7.50339

eV/atom

Energy above Hull

0.0978

eV/atom

Uncorrected Energy

-6.6359

eV/atom

Volume/atom

10.77

Å³

c/a Ratio

1.6219

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

4.0001

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.015470

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

O · 0.667

Element Family

Metalloid-Nonmetal

Solute Fraction

0.333

Interstitial Fraction

0.000

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

0.8240

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

6.8504

J/mol·K

Ω Parameter

2.3271

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

40.195%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.7716

smaller = more stable mixing

VEC

5.333

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-2.083

kJ/mol; negative = exothermic mixing

Entropy Norm

0.7500

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.575

Family

O-rich Multi-Component

Matrix Element

O · 0.667

Related Tasks

Related computation task IDs (2)

aaabveij aaaefpfd

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-757799

Reference Citation

The crystal structure and related material properties of NbCo3O8 were obtained from the Materials Project database (MP-ID: mp-757799, 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_NbCo3O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.68936079
_cell_length_b   5.68936079
_cell_length_c   9.22778414
_cell_angle_alpha   89.91450500
_cell_angle_beta   89.91450500
_cell_angle_gamma   120.03884500
_symmetry_Int_Tables_number   1
_chemical_formula_structural   NbCo3O8
_chemical_formula_sum   'Nb2 Co6 O16'
_cell_volume   258.57286338
_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
  Nb  Nb0  1  0.66583300  0.33222400  0.50092300  1.0
  Nb  Nb1  1  0.33222400  0.66583300  0.00092300  1.0
  Co  Co2  1  0.33775500  0.16892800  0.78430800  1.0
  Co  Co3  1  0.83111800  0.66233400  0.78436300  1.0
  Co  Co4  1  0.83140400  0.16891400  0.78432100  1.0
  Co  Co5  1  0.16891400  0.83140400  0.28432100  1.0
  Co  Co6  1  0.16892800  0.33775500  0.28430800  1.0
  Co  Co7  1  0.66233400  0.83111800  0.28436300  1.0
  O  O8  1  0.32572500  0.16305700  0.39864000  1.0
  O  O9  1  0.51884300  0.48286900  0.67108700  1.0
  O  O10  1  0.66599000  0.33248900  0.88758600  1.0
  O  O11  1  0.00058100  0.00066500  0.69249200  1.0
  O  O12  1  0.00066500  0.00058100  0.19249200  1.0
  O  O13  1  0.83654200  0.67359200  0.39851100  1.0
  O  O14  1  0.51867200  0.03625900  0.67079600  1.0
  O  O15  1  0.96394500  0.48246900  0.67094900  1.0
  O  O16  1  0.16314200  0.83644700  0.89816600  1.0
  O  O17  1  0.83644700  0.16314200  0.39816600  1.0
  O  O18  1  0.03625900  0.51867200  0.17079600  1.0
  O  O19  1  0.48246900  0.96394500  0.17094900  1.0
  O  O20  1  0.33248900  0.66599000  0.38758600  1.0
  O  O21  1  0.16305700  0.32572500  0.89864000  1.0
  O  O22  1  0.48286900  0.51884300  0.17108700  1.0
  O  O23  1  0.67359200  0.83654200  0.89851100  1.0

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