Na2CoO3
High-Entropy Materials HEA Traditional Materials TRAMP-ID: mp-777786 · Space group: Cmc2_1 (#36)
Basic Information
Formula
Na2CoO3
MP-ID
mp-777786
Elements
3
Sites
24
Density
3.0521
g/cm³
Volume
332.77
ų
Cell a
5.0156
Å
Cell b
10.7182
Å
Cell c
6.1902
Å
α Angle
90.30
°
β Angle
90.00
°
γ Angle
90.00
°
Space Group
Cmc2_1
Point Group
mm2
Crystal System
Orthorhombic
Bravais Lattice
oC
Stability
Yes
Packing Fraction
-
X-ray Diffraction
Diffraction Pattern
X-axis: 2θ (°); Y-axis: relative intensity; Cu Kα ; λ=1.5418 Å
Diffraction Peaks (Top 24)
| 2θ | d (Å) | I | hkl |
|---|---|---|---|
| 16.50 | 5.3724 | 25.4 | (0,1,-1) |
| 16.54 | 5.3591 | 25.3 | (0,2,0) |
| 16.58 | 5.3484 | 98.6 | (0,1,1) |
| 24.28 | 3.6662 | 29.9 | (1,-1,1) |
| 24.28 | 3.6662 | 29.9 | (1,1,-1) |
| 24.31 | 3.6620 | 30.1 | (1,-2,0) |
| 24.31 | 3.6620 | 30.1 | (1,2,0) |
| 28.79 | 3.1013 | 57.4 | (0,3,-1) |
| 28.85 | 3.0950 | 59.0 | (0,0,2) |
| 28.92 | 3.0874 | 59.9 | (0,3,1) |
| 33.51 | 2.6742 | 2.3 | (0,2,2) |
| 33.99 | 2.6378 | 27.3 | (1,-3,1) |
| 33.99 | 2.6377 | 27.3 | (1,3,-1) |
| 34.04 | 2.6339 | 25.7 | (1,0,2) |
| 34.04 | 2.6339 | 25.7 | (1,0,-2) |
| 34.10 | 2.6292 | 25.1 | (1,3,1) |
| 34.10 | 2.6292 | 25.1 | (1,-3,-1) |
| 35.81 | 2.5078 | 100.0 | (2,0,0) |
| 38.00 | 2.3680 | 5.0 | (1,-2,2) |
| 38.00 | 2.3680 | 5.0 | (1,2,-2) |
| 38.08 | 2.3634 | 4.9 | (1,-4,0) |
| 38.08 | 2.3634 | 4.9 | (1,4,0) |
| 39.70 | 2.2706 | 4.5 | (2,1,1) |
| 39.70 | 2.2706 | 4.5 | (2,-1,-1) |
Energy Properties
Formation Energy/atom
-1.51471
eV/atom
Energy/atom
-5.62484
eV/atom
Energy above Hull
0.0000
eV/atom
Uncorrected Energy
-7.8502
eV/atom
Volume/atom
13.87
ų
c/a Ratio
1.2342
Electronic Properties
Metallic
Metal
Band Gap
0
eV
Direct Gap
No
CBM
N/A
eV
Magnetic Properties
Magnetic
Yes
Total Mag. Moment
0.0000
μB
Mag. Ordering
AFM
Mag. Sites
12
Magnetization/Volume
0.000000
μB/ų
Elastic Properties
Elastic data not available
Feature Analysis
Composition Overview
Element Composition (atomic fraction)
Composition Info
Major / Matrix Element
O · 0.500
Element Family
Metalloid-Nonmetal
Solute Fraction
0.500
Interstitial Fraction
0.000
High-Entropy Alloy Features
Composite Radar (normalized)
Element-Class Share
Mix Entropy ΔS/R
1.0114
HEA criterion (>1.0 = high entropy)
Mix Entropy ΔS
8.4088
J/mol·K
Ω Parameter
1.0769
Ω > 1.1 favors solid solution
Atomic Size Mismatch δr
50.172%
δr < 6.6% favors single-phase solid solution
Electronegativity Diff Δχ
1.1415
smaller = more stable mixing
VEC
3.833
valence electron concentration, affects phase stability
Mix Enthalpy ΔH_mix
-3.480
kJ/mol; negative = exothermic mixing
Entropy Norm
0.9206
SS Former
0
Phase Tendency
IM
Traditional Material Features
ROM Blended-Feature Radar
Rating & Classification
Tier
B
Score
0.465
Family
O-rich Multi-Component
Matrix Element
O · 0.500
Related Tasks
Citation & References
Materials Project Page
https://materialsproject.org/materials/mp-777786
Reference Citation
The crystal structure and related material properties of Na2CoO3 were obtained from the Materials Project database (MP-ID: mp-777786, 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
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Raw CIF Data
# generated using pymatgen
data_Na2CoO3
_symmetry_space_group_name_H-M 'P 1'
_cell_length_a 5.01560981
_cell_length_b 10.71823802
_cell_length_c 6.19014982
_cell_angle_alpha 90.29656017
_cell_angle_beta 89.99947253
_cell_angle_gamma 90.00004988
_symmetry_Int_Tables_number 1
_chemical_formula_structural Na2CoO3
_chemical_formula_sum 'Na8 Co4 O12'
_cell_volume 332.76871013
_cell_formula_units_Z 4
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 0.51627439 0.75250151 0.91994970 1.0
Na Na1 1 0.51621364 0.25250672 0.41998452 1.0
Na Na2 1 0.01502430 0.58364512 0.09112541 1.0
Na Na3 1 0.01500429 0.08364010 0.59115378 1.0
Na Na4 1 0.51500044 0.41635930 0.90885735 1.0
Na Na5 1 0.51502154 0.91636144 0.40885721 1.0
Na Na6 1 0.01621060 0.24747511 0.08001033 1.0
Na Na7 1 0.01627435 0.74751529 0.58004686 1.0
Co Co8 1 0.05281151 0.91772064 0.08226876 1.0
Co Co9 1 0.55284543 0.58225312 0.41777038 1.0
Co Co10 1 0.05283446 0.41772259 0.58221946 1.0
Co Co11 1 0.55280600 0.08229359 0.91775026 1.0
O O12 1 0.40614488 0.44850731 0.55105697 1.0
O O13 1 0.40616703 0.94850615 0.05106957 1.0
O O14 1 0.90616268 0.05150012 0.94891653 1.0
O O15 1 0.90614102 0.55148163 0.44895395 1.0
O O16 1 0.98388970 0.77820190 0.94504521 1.0
O O17 1 0.98385730 0.27817741 0.44502695 1.0
O O18 1 0.48389995 0.58281663 0.14051537 1.0
O O19 1 0.48387600 0.08283287 0.64051022 1.0
O O20 1 0.98387921 0.41715790 0.85948929 1.0
O O21 1 0.98389516 0.91719874 0.35948113 1.0
O O22 1 0.48386888 0.22180951 0.05497431 1.0
O O23 1 0.48389525 0.72181332 0.55496546 1.0
