Co3BiO8

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-756635 · Space group: R-3m (#166)

Materials Project API

Basic Information

Formula

Co3BiO8

MP-ID

mp-756635

Elements

Sites

Density

5.8593

g/cm³

Volume

145.61

Å³

Cell a

6.1917

Cell b

6.1917

Cell c

6.1917

α Angle

54.32

β Angle

54.32

γ Angle

54.32

Space Group

R-3m

Point Group

-3m

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
18.98	4.6757	100.0	(1,0,0)
21.36	4.1602	18.9	(1,1,0)
29.06	3.0724	8.3	(2,1,1)
31.66	2.8264	2.6	(1,-1,0)
31.66	2.8264	5.1	(1,0,-1)
33.78	2.6532	22.3	(2,2,1)
34.08	2.6309	8.6	(2,2,2)
36.07	2.4899	35.8	(2,1,0)
38.51	2.3379	15.6	(2,0,0)
43.51	2.0801	38.2	(2,2,0)
44.22	2.0482	9.6	(3,2,2)
46.97	1.9344	1.0	(3,1,1)
47.20	1.9257	5.8	(3,2,1)
49.61	1.8377	13.8	(2,0,-1)
49.83	1.8301	2.1	(3,3,2)
50.67	1.8015	4.6	(2,1,-1)
54.80	1.6753	3.7	(3,1,0)
56.38	1.6318	1.1	(2,-1,-1)
57.75	1.5963	11.0	(3,2,0)
59.29	1.5586	8.7	(3,0,0)
60.24	1.5362	7.7	(4,2,2)
60.24	1.5362	3.9	(2,2,4)
61.75	1.5024	1.6	(4,3,3)
62.30	1.4903	8.0	(4,3,2)

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Energy Properties

Formation Energy/atom

-1.08481

eV/atom

Energy/atom

-6.49098

eV/atom

Energy above Hull

0.0864

eV/atom

Uncorrected Energy

-5.6235

eV/atom

Volume/atom

12.13

Å³

c/a Ratio

1.0000

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

1.9951

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.013700

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

1.8662

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

42.385%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.7197

smaller = more stable mixing

VEC

5.333

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

1.923

kJ/mol; negative = exothermic mixing

Entropy Norm

0.7500

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.583

Family

O-rich Multi-Component

Matrix Element

O · 0.667

Related Tasks

Related computation task IDs (5)

aaadqeda aaadvftk aaadxhta aaaeplon aaafazbs

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-756635

Reference Citation

The crystal structure and related material properties of Co3BiO8 were obtained from the Materials Project database (MP-ID: mp-756635, 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_Co3BiO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.19171748
_cell_length_b   6.19171748
_cell_length_c   6.19171731
_cell_angle_alpha   54.31981238
_cell_angle_beta   54.31981238
_cell_angle_gamma   54.31981461
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Co3BiO8
_chemical_formula_sum   'Co3 Bi1 O8'
_cell_volume   145.60611805
_cell_formula_units_Z   1
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
  Co  Co0  1  0.00000000  0.50000000  0.50000000  1.0
  Co  Co1  1  0.50000000  0.00000000  0.50000000  1.0
  Co  Co2  1  0.50000000  0.50000000  0.00000000  1.0
  Bi  Bi3  1  0.50000000  0.50000000  0.50000000  1.0
  O  O4  1  0.24377200  0.71273500  0.24377200  1.0
  O  O5  1  0.71273500  0.24377200  0.24377200  1.0
  O  O6  1  0.72402100  0.72402100  0.72402100  1.0
  O  O7  1  0.24377200  0.24377200  0.71273500  1.0
  O  O8  1  0.75622800  0.75622800  0.28726500  1.0
  O  O9  1  0.27597900  0.27597900  0.27597900  1.0
  O  O10  1  0.28726500  0.75622800  0.75622800  1.0
  O  O11  1  0.75622800  0.28726500  0.75622800  1.0

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