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Na8Si7O18

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-652025 · Space group: P1 (#1)

Basic Information

Formula
Na8Si7O18
MP-ID
mp-652025
Elements
3
Sites
33
Density
1.9571
g/cm³
Volume
567.21
ų
Cell a
6.2781
Å
Cell b
9.0687
Å
Cell c
10.9707
Å
α Angle
103.33
°
β Angle
101.12
°
γ Angle
104.51
°
Space Group
P1
Point Group
1
Crystal System
Triclinic
Bravais Lattice
Triclinic P
Stability
No
Packing Fraction
0.5240

X-ray Diffraction

Diffraction Pattern
X-axis: 2θ (°); Y-axis: relative intensity; CuKa ; λ=1.5406 Å
Diffraction Peaks (Top 24)
2θd (Å)Ihkl
10.54 8.3928 100.0 (0,1,0)
15.12 5.8590 44.1 (1,0,0)
15.28 5.7976 35.7 (1,0,-1)
15.46 5.7320 2.3 (0,1,1)
15.54 5.7015 24.0 (1,-1,0)
17.23 5.1454 3.8 (0,0,2)
17.33 5.1178 35.3 (1,-1,-1)
17.37 5.1048 36.7 (0,1,-2)
18.23 4.8661 5.0 (1,-1,1)
19.32 4.5933 2.5 (1,0,1)
19.70 4.5057 1.5 (1,0,-2)
19.80 4.4849 19.6 (1,1,-1)
20.37 4.3587 7.0 (0,2,-1)
21.00 4.2298 13.6 (1,1,0)
21.17 4.1964 5.4 (0,2,0)
21.91 4.0560 4.5 (1,-2,0)
22.58 3.9380 3.7 (1,-1,-2)
22.75 3.9085 3.5 (1,-2,1)
22.77 3.9055 5.7 (0,1,2)
23.09 3.8527 1.9 (0,2,-2)
23.98 3.7117 2.3 (1,-1,2)
24.38 3.6515 4.6 (1,-2,-1)
25.00 3.5625 1.3 (0,1,-3)
25.16 3.5394 7.0 (0,2,1)
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Energy Properties

Formation Energy/atom
-1.89400
eV/atom
Energy/atom
-6.06898
eV/atom
Energy above Hull
0.9707
eV/atom
Uncorrected Energy
-5.9812
eV/atom
Volume/atom
17.19
ų
c/a Ratio
-

Electronic Properties

Metallic
Metal
Band Gap
0
eV
Direct Gap
No
CBM
N/A
eV

Magnetic Properties

Magnetic
No
Total Mag. Moment
0.5552
μB
Mag. Ordering
NM
Mag. Sites
0
Magnetization/Volume
0.000980
μB/ų

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)
Composition Info
Major / Matrix Element
O · 0.545
Element Family
Metalloid-Nonmetal
Solute Fraction
0.455
Interstitial Fraction
0.212

High-Entropy Alloy Features

Composite Radar (normalized)
Element-Class Share
Mix Entropy ΔS/R
1.0031
HEA criterion (>1.0 = high entropy)
Mix Entropy ΔS
8.3395
J/mol·K
Ω Parameter
0.5433
Ω > 1.1 favors solid solution
Atomic Size Mismatch δr
50.814%
δr < 6.6% favors single-phase solid solution
Electronegativity Diff Δχ
1.0751
smaller = more stable mixing
VEC
3.273
valence electron concentration, affects phase stability
Mix Enthalpy ΔH_mix
-7.332
kJ/mol; negative = exothermic mixing
Entropy Norm
0.9130
SS Former
0
Phase Tendency
IM

Traditional Material Features

ROM Blended-Feature Radar
Rating & Classification
Tier
C
Score
0.294
Family
Interstitial Alloy
Matrix Element
O · 0.545

Related Tasks

Related computation task IDs (1)

Citation & References

Materials Project Page
https://materialsproject.org/materials/mp-652025
Reference Citation

The crystal structure and related material properties of Na8Si7O18 were obtained from the Materials Project database (MP-ID: mp-652025, 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

BibTeX
@article{Horton2025,
  author  = {Horton, Matthew K. and Huck, Patrick and Yang, Ruo Xi and Munro, Jason M. and Dwaraknath, Shyam and Ganose, Alex M. and Kingsbury, Ryan S. and Wen, Mingjian and Shen, Jimmy X. and Mathis, Tyler S. and Kaplan, Aaron D. and Berket, Karlo and Riebesell, Janosh and George, Janine and Rosen, Andrew S. and Spotte-Smith, Evan W. C. and McDermott, Matthew J. and Cohen, Orion A. and Dunn, Alex and Kuner, Matthew C. and Rignanese, Gian-Marco and Petretto, Guido and Waroquiers, David and Griffin, Sinead M. and Neaton, Jeffrey B. and Chrzan, Daryl C. and Asta, Mark and Hautier, Geoffroy and Cholia, Shreyas and Ceder, Gerbrand and Ong, Shyue Ping and Jain, Anubhav and Persson, Kristin A.},
  title   = {Accelerated data-driven materials science with the Materials Project},
  journal = {Nature Materials},
  year    = {2025},
  volume  = {24},
  number  = {10},
  pages   = {1522--1532},
  month   = {oct},
  doi     = {10.1038/s41563-025-02272-0},
  issn    = {1476-4660},
  url     = {https://doi.org/10.1038/s41563-025-02272-0},
  abstract = {The Materials Project was launched formally in 2011 to drive materials discovery forwards through high-throughput computation and open data. More than a decade later, the Materials Project has become an indispensable tool used by more than 600,000 materials researchers around the world. This Perspective describes how the Materials Project, as a data platform and a software ecosystem, has helped to shape research in data-driven materials science. We cover how sustainable software and computational methods have accelerated materials design while becoming more open source and collaborative in nature. Next, we present cases where the Materials Project was used to understand and discover functional materials. We then describe our efforts to meet the needs of an expanding user base, through technical infrastructure updates ranging from data architecture and cloud resources to interactive web applications. Finally, we discuss opportunities to better aid the research community, with the vision that more accessible and easy-to-understand materials data will result in democratized materials knowledge and an increasingly collaborative community.}
}

3D Crystal Structure Rendering

Loading 3D structure…

Style: Ball & Stick
Raw CIF Data
# generated using pymatgen
data_Na8Si7O18
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.27812200
_cell_length_b   9.06869643
_cell_length_c   10.97065986
_cell_angle_alpha   103.32741023
_cell_angle_beta   101.11638746
_cell_angle_gamma   104.50908253
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na8Si7O18
_chemical_formula_sum   'Na8 Si7 O18'
_cell_volume   567.20898650
_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
  Na  Na0  1  0.27159800  0.70438900  0.26324100  1.0
  Na  Na1  1  0.58254400  0.31138700  0.72361900  1.0
  Na  Na2  1  0.46585000  0.54908900  0.96568300  1.0
  Na  Na3  1  0.94708400  0.87337500  0.46320700  1.0
  Na  Na4  1  0.40438100  0.48456800  0.47960300  1.0
  Na  Na5  1  0.96016100  0.43516100  0.99096900  1.0
  Na  Na6  1  0.57822500  0.11001800  0.48496700  1.0
  Na  Na7  1  0.91997000  0.56709800  0.54871000  1.0
  Si  Si8  1  0.97185200  0.01950100  0.01125400  1.0
  Si  Si9  1  0.94083900  0.69066000  0.85574200  1.0
  Si  Si10  1  0.79022000  0.54022700  0.26466700  1.0
  Si  Si11  1  0.12031700  0.08877200  0.25790700  1.0
  Si  Si12  1  0.34888200  0.33395000  0.15414000  1.0
  Si  Si13  1  0.09631200  0.36515300  0.68557500  1.0
  Si  Si14  1  0.78528600  0.93211600  0.75181700  1.0
  O  O15  1  0.28709200  0.48455900  0.12954200  1.0
  O  O16  1  0.87940000  0.63603400  0.17012000  1.0
  O  O17  1  0.70737900  0.96341900  0.61847100  1.0
  O  O18  1  0.75506400  0.54382900  0.86384500  1.0
  O  O19  1  0.12451000  0.33118900  0.82464400  1.0
  O  O20  1  0.20424400  0.99539500  0.35213700  1.0
  O  O21  1  0.26021700  0.31255400  0.59753800  1.0
  O  O22  1  0.19959800  0.16702000  0.03175000  1.0
  O  O23  1  0.83562800  0.33519500  0.60208000  1.0
  O  O24  1  0.68904700  0.62266000  0.37892000  1.0
  O  O25  1  0.02061000  0.84792100  0.98649700  1.0
  O  O26  1  0.17114300  0.62999700  0.43312900  1.0
  O  O27  1  0.00470500  0.47945000  0.34407700  1.0
  O  O28  1  0.61976900  0.35206100  0.17524600  1.0
  O  O29  1  0.28870800  0.26964200  0.28193600  1.0
  O  O30  1  0.21670200  0.58147000  0.72426100  1.0
  O  O31  1  0.20335500  0.67915700  0.85236800  1.0
  O  O32  1  0.84930900  0.76298400  0.73233500  1.0
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