Nb6SI9
High-Entropy Materials HEA Traditional Materials TRAMP-ID: mp-654051 · Space group: P-1 (#2)
Basic Information
Formula
Nb6SI9
MP-ID
mp-654051
Elements
3
Sites
32
Density
5.3035
g/cm³
Volume
1,084.36
ų
Cell a
10.3573
Å
Cell b
10.8162
Å
Cell c
11.9706
Å
α Angle
106.07
°
β Angle
104.71
°
γ Angle
112.83
°
Space Group
P-1
Point Group
-1
Crystal System
Triclinic
Bravais Lattice
aP
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 |
|---|---|---|---|
| 9.86 | 8.9692 | 97.8 | (0,1,-1) |
| 10.04 | 8.8107 | 100.0 | (1,-1,0) |
| 10.15 | 8.7154 | 1.1 | (1,0,0) |
| 10.21 | 8.6653 | 76.5 | (1,0,-1) |
| 13.10 | 6.7573 | 2.3 | (1,-1,-1) |
| 15.39 | 5.7579 | 4.2 | (0,1,1) |
| 15.64 | 5.6664 | 4.9 | (1,0,1) |
| 15.75 | 5.6252 | 1.4 | (1,0,-2) |
| 16.88 | 5.2512 | 7.0 | (0,0,2) |
| 17.13 | 5.1773 | 2.6 | (1,-2,1) |
| 17.27 | 5.1360 | 6.9 | (1,1,0) |
| 17.43 | 5.0889 | 4.2 | (1,1,-2) |
| 17.73 | 5.0020 | 2.1 | (2,-1,-1) |
| 19.64 | 4.5212 | 1.7 | (0,2,0) |
| 19.66 | 4.5152 | 1.6 | (1,-1,-2) |
| 19.70 | 4.5064 | 1.5 | (1,-1,2) |
| 19.80 | 4.4846 | 15.4 | (0,2,-2) |
| 20.16 | 4.4054 | 20.9 | (2,-2,0) |
| 20.50 | 4.3327 | 14.6 | (2,0,-2) |
| 20.82 | 4.2662 | 2.9 | (1,-2,-1) |
| 21.38 | 4.1562 | 2.6 | (2,-1,1) |
| 23.06 | 3.8568 | 1.0 | (0,1,-3) |
| 23.07 | 3.8559 | 1.5 | (1,0,2) |
| 23.46 | 3.7923 | 1.6 | (1,2,-1) |
Energy Properties
Formation Energy/atom
-0.80797
eV/atom
Energy/atom
-5.71181
eV/atom
Energy above Hull
0.0000
eV/atom
Uncorrected Energy
-24.2816
eV/atom
Volume/atom
33.89
ų
c/a Ratio
1.1558
Electronic Properties
Metallic
Metal
Band Gap
0
eV
Direct Gap
No
CBM
N/A
eV
Magnetic Properties
Magnetic
Yes
Total Mag. Moment
0.0735
μB
Mag. Ordering
AFM
Mag. Sites
12
Magnetization/Volume
0.000070
μB/ų
Elastic Properties
Elastic data not available
Feature Analysis
Composition Overview
Element Composition (atomic fraction)
Composition Info
Major / Matrix Element
I · 0.563
Element Family
Metalloid-Nonmetal
Solute Fraction
0.438
Interstitial Fraction
0.000
High-Entropy Alloy Features
Composite Radar (normalized)
Element-Class Share
Mix Entropy ΔS/R
0.8647
HEA criterion (>1.0 = high entropy)
Mix Entropy ΔS
7.1894
J/mol·K
Ω Parameter
2.6780
Ω > 1.1 favors solid solution
Atomic Size Mismatch δr
7.112%
δr < 6.6% favors single-phase solid solution
Electronegativity Diff Δχ
0.5097
smaller = more stable mixing
VEC
5.063
valence electron concentration, affects phase stability
Mix Enthalpy ΔH_mix
-3.418
kJ/mol; negative = exothermic mixing
Entropy Norm
0.7871
SS Former
0
Phase Tendency
IM
Traditional Material Features
ROM Blended-Feature Radar
Rating & Classification
Tier
B
Score
0.578
Family
I-rich Multi-Component
Matrix Element
I · 0.563
Related Tasks
Citation & References
Materials Project Page
https://materialsproject.org/materials/mp-654051
Reference Citation
The crystal structure and related material properties of Nb6SI9 were obtained from the Materials Project database (MP-ID: mp-654051, 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_Nb6SI9
_symmetry_space_group_name_H-M 'P 1'
_cell_length_a 10.35728132
_cell_length_b 10.81622023
_cell_length_c 11.97062483
_cell_angle_alpha 106.06689346
_cell_angle_beta 104.70887073
_cell_angle_gamma 112.83168648
_symmetry_Int_Tables_number 1
_chemical_formula_structural Nb6SI9
_chemical_formula_sum 'Nb12 S2 I18'
_cell_volume 1084.35866492
_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 0.61113931 0.73849408 0.03997711 1.0
Nb Nb1 1 0.10213164 0.97549806 0.67362084 1.0
Nb Nb2 1 0.98355079 0.14803366 0.59042518 1.0
Nb Nb3 1 0.76634444 0.84611802 0.47166628 1.0
Nb Nb4 1 0.01644921 0.85196634 0.40957482 1.0
Nb Nb5 1 0.47878497 0.55853214 0.18498737 1.0
Nb Nb6 1 0.32073648 0.48498396 0.92778876 1.0
Nb Nb7 1 0.89786836 0.02450194 0.32637916 1.0
Nb Nb8 1 0.23365556 0.15388198 0.52833372 1.0
Nb Nb9 1 0.38886069 0.26150592 0.96002289 1.0
Nb Nb10 1 0.67926352 0.51501604 0.07221124 1.0
Nb Nb11 1 0.52121503 0.44146786 0.81501263 1.0
S S12 1 0.25901359 0.24430023 0.74944669 1.0
S S13 1 0.74098641 0.75569977 0.25055331 1.0
I I14 1 0.32218722 0.94129032 0.57522339 1.0
I I15 1 0.57507585 0.34778106 0.21883609 1.0
I I16 1 0.10700709 0.33436445 0.46395823 1.0
I I17 1 0.17447585 0.31188521 0.05591122 1.0
I I18 1 0.82552415 0.68811479 0.94408878 1.0
I I19 1 0.24295134 0.94821314 0.90198196 1.0
I I20 1 0.89299291 0.66563555 0.53604177 1.0
I I21 1 0.54280707 0.35581938 0.57209749 1.0
I I22 1 -0.00637068 0.58266249 0.22785673 1.0
I I23 1 0.75704866 0.05178686 0.09801804 1.0
I I24 1 0.36906559 0.74872339 0.11720705 1.0
I I25 1 0.67781278 0.05870968 0.42477661 1.0
I I26 1 0.00637068 0.41733751 0.77214327 1.0
I I27 1 0.85682321 0.99574429 0.73906371 1.0
I I28 1 0.45719293 0.64418062 0.42790251 1.0
I I29 1 0.14317679 0.00425571 0.26093629 1.0
I I30 1 0.42492415 0.65221894 0.78116391 1.0
I I31 1 0.63093441 0.25127661 0.88279295 1.0
