Na8Cu2O7
High-Entropy Materials HEA Traditional Materials TRAMP-ID: mp-779159 · Space group: P2_1/c (#14)
Basic Information
Formula
Na8Cu2O7
MP-ID
mp-779159
Elements
3
Sites
68
Density
3.0484
g/cm³
Volume
921.69
ų
Cell a
11.0746
Å
Cell b
8.6577
Å
Cell c
10.0084
Å
α Angle
73.84
°
β Angle
90.00
°
γ Angle
90.00
°
Space Group
P2_1/c
Point Group
2/m
Crystal System
Monoclinic
Bravais Lattice
mP
Stability
No
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 |
|---|---|---|---|
| 10.64 | 8.3156 | 19.7 | (0,1,0) |
| 13.31 | 6.6497 | 14.6 | (1,1,0) |
| 14.41 | 6.1461 | 2.2 | (1,1,1) |
| 16.01 | 5.5373 | 69.5 | (2,0,0) |
| 18.46 | 4.8065 | 15.5 | (0,0,2) |
| 18.49 | 4.7982 | 11.3 | (2,0,1) |
| 18.57 | 4.7770 | 51.7 | (0,1,2) |
| 19.26 | 4.6090 | 2.6 | (2,1,0) |
| 20.04 | 4.4309 | 17.0 | (2,1,1) |
| 20.14 | 4.4091 | 7.3 | (1,0,2) |
| 20.25 | 4.3864 | 3.0 | (1,1,2) |
| 21.37 | 4.1578 | 3.7 | (0,2,0) |
| 22.30 | 3.9874 | 3.7 | (1,2,1) |
| 22.85 | 3.8925 | 80.5 | (1,2,0) |
| 24.09 | 3.6941 | 3.6 | (0,2,2) |
| 24.52 | 3.6298 | 25.3 | (2,0,2) |
| 24.61 | 3.6170 | 39.6 | (2,1,2) |
| 25.16 | 3.5394 | 3.2 | (1,1,-2) |
| 25.42 | 3.5043 | 1.0 | (1,2,2) |
| 26.81 | 3.3249 | 1.2 | (2,2,0) |
| 26.86 | 3.3196 | 12.2 | (1,2,-1) |
| 28.83 | 3.0966 | 1.7 | (2,1,-2) |
| 29.01 | 3.0781 | 2.5 | (1,0,3) |
| 29.02 | 3.0769 | 1.0 | (3,1,-1) |
Energy Properties
Formation Energy/atom
-1.33679
eV/atom
Energy/atom
-4.48784
eV/atom
Energy above Hull
0.1028
eV/atom
Uncorrected Energy
-4.2050
eV/atom
Volume/atom
13.55
ų
c/a Ratio
0.9037
Electronic Properties
Metallic
Metal
Band Gap
0
eV
Direct Gap
No
CBM
N/A
eV
Magnetic Properties
Magnetic
Yes
Total Mag. Moment
15.9928
μB
Mag. Ordering
FM
Mag. Sites
36
Magnetization/Volume
0.017350
μB/ų
Elastic Properties
Elastic data not available
Feature Analysis
Composition Overview
Element Composition (atomic fraction)
Composition Info
Major / Matrix Element
Na · 0.471
Element Family
Alkali-AlkEarth
Solute Fraction
0.529
Interstitial Fraction
0.000
High-Entropy Alloy Features
Composite Radar (normalized)
Element-Class Share
Mix Entropy ΔS/R
0.9718
HEA criterion (>1.0 = high entropy)
Mix Entropy ΔS
8.0800
J/mol·K
Ω Parameter
0.4275
Ω > 1.1 favors solid solution
Atomic Size Mismatch δr
46.386%
δr < 6.6% favors single-phase solid solution
Electronegativity Diff Δχ
1.1780
smaller = more stable mixing
VEC
3.412
valence electron concentration, affects phase stability
Mix Enthalpy ΔH_mix
-6.746
kJ/mol; negative = exothermic mixing
Entropy Norm
0.8846
SS Former
0
Phase Tendency
IM
Traditional Material Features
ROM Blended-Feature Radar
Rating & Classification
Tier
C
Score
0.390
Family
Na-rich Multi-Component
Matrix Element
Na · 0.471
Related Tasks
Related computation task IDs (1)
Citation & References
Materials Project Page
https://materialsproject.org/materials/mp-779159
Reference Citation
The crystal structure and related material properties of Na8Cu2O7 were obtained from the Materials Project database (MP-ID: mp-779159, 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_Na8Cu2O7
_symmetry_space_group_name_H-M 'P 1'
_cell_length_a 11.07455100
_cell_length_b 8.65766100
_cell_length_c 10.00838387
_cell_angle_alpha 73.84078479
_cell_angle_beta 90.00000000
_cell_angle_gamma 90.00000000
_symmetry_Int_Tables_number 1
_chemical_formula_structural Na8Cu2O7
_chemical_formula_sum 'Na32 Cu8 O28'
_cell_volume 921.68904699
_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 0.52216100 0.87923600 0.92079500 1.0
Na Na1 1 0.53991700 0.91991800 0.64610700 1.0
Na Na2 1 0.25935900 0.89065100 0.53396100 1.0
Na Na3 1 0.97783900 0.87923600 0.42079500 1.0
Na Na4 1 0.05182800 0.74089200 0.71456000 1.0
Na Na5 1 0.96008300 0.91991800 0.14610700 1.0
Na Na6 1 0.75061400 0.71139900 0.57027100 1.0
Na Na7 1 0.24064100 0.89065100 0.03396100 1.0
Na Na8 1 0.52479300 0.56964800 0.85775000 1.0
Na Na9 1 0.49602500 0.66026100 0.51560200 1.0
Na Na10 1 0.44817200 0.74089200 0.21456000 1.0
Na Na11 1 0.76768900 0.49241400 0.87476400 1.0
Na Na12 1 0.74938600 0.71139900 0.07027100 1.0
Na Na13 1 0.26768900 0.50758600 0.62523600 1.0
Na Na14 1 0.97520700 0.56964800 0.35775000 1.0
Na Na15 1 0.99602500 0.33973900 0.98439800 1.0
Na Na16 1 0.00397500 0.66026100 0.01560200 1.0
Na Na17 1 0.02479300 0.43035200 0.64225000 1.0
Na Na18 1 0.73231100 0.49241400 0.37476400 1.0
Na Na19 1 0.25061400 0.28860100 0.92972900 1.0
Na Na20 1 0.23231100 0.50758600 0.12523600 1.0
Na Na21 1 0.55182800 0.25910800 0.78544000 1.0
Na Na22 1 0.50397500 0.33973900 0.48439800 1.0
Na Na23 1 0.47520700 0.43035200 0.14225000 1.0
Na Na24 1 0.75935900 0.10934900 0.96603900 1.0
Na Na25 1 0.24938600 0.28860100 0.42972900 1.0
Na Na26 1 0.03991700 0.08008200 0.85389300 1.0
Na Na27 1 0.94817200 0.25910800 0.28544000 1.0
Na Na28 1 0.02216100 0.12076400 0.57920500 1.0
Na Na29 1 0.74064100 0.10934900 0.46603900 1.0
Na Na30 1 0.46008300 0.08008200 0.35389300 1.0
Na Na31 1 0.47783900 0.12076400 0.07920500 1.0
Cu Cu32 1 0.79867800 0.90719400 0.77407300 1.0
Cu Cu33 1 0.70132200 0.90719400 0.27407300 1.0
Cu Cu34 1 0.28133900 0.69017500 0.84676900 1.0
Cu Cu35 1 0.21866100 0.69017500 0.34676900 1.0
Cu Cu36 1 0.78133900 0.30982500 0.65323100 1.0
Cu Cu37 1 0.71866100 0.30982500 0.15323100 1.0
Cu Cu38 1 0.29867800 0.09280600 0.72592700 1.0
Cu Cu39 1 0.20132200 0.09280600 0.22592700 1.0
O O40 1 0.88915600 0.89059200 0.93564100 1.0
O O41 1 0.19357000 0.89661100 0.78976800 1.0
O O42 1 0.88965800 0.89951300 0.61910800 1.0
O O43 1 0.61084400 0.89059200 0.43564100 1.0
O O44 1 0.67686100 0.74765300 0.81974000 1.0
O O45 1 0.30643000 0.89661100 0.28976800 1.0
O O46 1 0.61034200 0.89951300 0.11910800 1.0
O O47 1 0.38781200 0.68827000 0.69850200 1.0
O O48 1 0.82313900 0.74765300 0.31974000 1.0
O O49 1 0.14479400 0.54222400 0.89470700 1.0
O O50 1 0.11009200 0.66768100 0.50542400 1.0
O O51 1 0.11218800 0.68827000 0.19850200 1.0
O O52 1 0.35520600 0.54222400 0.39470700 1.0
O O53 1 0.61009200 0.33231900 0.99457600 1.0
O O54 1 0.38990800 0.66768100 0.00542400 1.0
O O55 1 0.64479400 0.45777600 0.60529300 1.0
O O56 1 0.88781200 0.31173000 0.80149800 1.0
O O57 1 0.88990800 0.33231900 0.49457600 1.0
O O58 1 0.85520600 0.45777600 0.10529300 1.0
O O59 1 0.17686100 0.25234700 0.68026000 1.0
O O60 1 0.61218800 0.31173000 0.30149800 1.0
O O61 1 0.38965800 0.10048700 0.88089200 1.0
O O62 1 0.69357000 0.10338900 0.71023200 1.0
O O63 1 0.32313900 0.25234700 0.18026000 1.0
O O64 1 0.38915600 0.10940800 0.56435900 1.0
O O65 1 0.11034200 0.10048700 0.38089200 1.0
O O66 1 0.80643000 0.10338900 0.21023200 1.0
O O67 1 0.11084400 0.10940800 0.06435900 1.0
