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KNb3F9

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-675780 · Space group: P1 (#1)

Basic Information

Formula
KNb3F9
MP-ID
mp-675780
Elements
3
Sites
26
Density
3.5097
g/cm³
Volume
462.53
ų
Cell a
7.9939
Å
Cell b
8.0038
Å
Cell c
8.3436
Å
α Angle
89.15
°
β Angle
89.00
°
γ Angle
60.06
°
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
12.76 6.9357 21.4 (0,1,-1,0)
12.78 6.9269 22.0 (1,0,-1,0)
12.79 6.9238 21.3 (1,1,-2,0)
21.30 4.1711 100.0 (0,0,0,2)
22.21 4.0032 11.8 (1,-1,0,0)
22.22 4.0015 10.7 (1,2,-3,0)
22.24 3.9964 11.7 (2,1,-3,0)
24.71 3.6026 12.3 (1,1,-2,2)
24.79 3.5918 10.7 (1,0,-1,2)
24.83 3.5856 11.4 (0,1,-1,2)
24.99 3.5635 11.3 (0,1,-1,-2)
25.05 3.5550 10.7 (1,0,-1,-2)
25.13 3.5438 10.6 (1,1,-2,-2)
25.69 3.4679 75.5 (0,2,-2,0)
25.72 3.4634 75.7 (2,0,-2,0)
25.73 3.4619 75.2 (2,2,-4,0)
30.71 2.9112 8.4 (2,1,-3,2)
30.73 2.9091 9.8 (1,2,-3,2)
30.92 2.8921 8.2 (1,-1,0,2)
31.00 2.8843 8.3 (1,-1,0,-2)
31.20 2.8665 9.8 (1,2,-3,-2)
31.27 2.8608 8.4 (2,1,-3,-2)
33.33 2.6886 6.8 (2,2,-4,2)
33.44 2.6800 7.9 (2,0,-2,2)
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Energy Properties

Formation Energy/atom
-2.77942
eV/atom
Energy/atom
-6.52300
eV/atom
Energy above Hull
0.2937
eV/atom
Uncorrected Energy
-6.2032
eV/atom
Volume/atom
17.79
ų
c/a Ratio
-

Electronic Properties

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

Magnetic Properties

Magnetic
Yes
Total Mag. Moment
13.9982
μB
Mag. Ordering
FM
Mag. Sites
6
Magnetization/Volume
0.030260
μB/ų

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)
Composition Info
Major / Matrix Element
F · 0.692
Element Family
Metalloid-Nonmetal
Solute Fraction
0.308
Interstitial Fraction
0.000

High-Entropy Alloy Features

Composite Radar (normalized)
Element-Class Share
Mix Entropy ΔS/R
0.7903
HEA criterion (>1.0 = high entropy)
Mix Entropy ΔS
6.5703
J/mol·K
Ω Parameter
0.0000
Ω > 1.1 favors solid solution
Atomic Size Mismatch δr
65.417%
δr < 6.6% favors single-phase solid solution
Electronegativity Diff Δχ
1.2031
smaller = more stable mixing
VEC
4.692
valence electron concentration, affects phase stability
Mix Enthalpy ΔH_mix
0.000
kJ/mol; negative = exothermic mixing
Entropy Norm
0.7193
SS Former
0
Phase Tendency
IM

Traditional Material Features

ROM Blended-Feature Radar
Rating & Classification
Tier
C
Score
0.445
Family
F-rich Multi-Component
Matrix Element
F · 0.692

Related Tasks

Related computation task IDs (2)

Citation & References

Materials Project Page
https://materialsproject.org/materials/mp-675780
Reference Citation

The crystal structure and related material properties of KNb3F9 were obtained from the Materials Project database (MP-ID: mp-675780, 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_KNb3F9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.99393200
_cell_length_b   8.00381558
_cell_length_c   8.34360836
_cell_angle_alpha   89.15385133
_cell_angle_beta   88.99914180
_cell_angle_gamma   60.06314690
_symmetry_Int_Tables_number   1
_chemical_formula_structural   KNb3F9
_chemical_formula_sum   'K2 Nb6 F18'
_cell_volume   462.53138467
_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
  K  K0  1  0.96839600  0.51835600  0.24528700  1.0
  K  K1  1  0.02236400  0.49512600  0.75034500  1.0
  Nb  Nb2  1  0.49818000  0.99945500  0.99589700  1.0
  Nb  Nb3  1  0.49934600  0.50020100  0.00328000  1.0
  Nb  Nb4  1  0.00020300  0.99945300  0.49965700  1.0
  Nb  Nb5  1  0.99979000  0.99994400  0.99988900  1.0
  Nb  Nb6  1  0.49945700  0.50017400  0.50321100  1.0
  Nb  Nb7  1  0.49934600  0.99997300  0.49623100  1.0
  F  F8  1  0.53846500  0.51200000  0.75252600  1.0
  F  F9  1  0.45727900  0.05262100  0.24598700  1.0
  F  F10  1  0.80614800  0.30595100  0.47765700  1.0
  F  F11  1  0.19285300  0.11294500  0.52036900  1.0
  F  F12  1  0.80724200  0.30774200  0.02951100  1.0
  F  F13  1  0.19328600  0.11108700  0.96361000  1.0
  F  F14  1  0.39456900  0.30121600  0.54258000  1.0
  F  F15  1  0.60384800  0.69794200  0.45695500  1.0
  F  F16  1  0.03967200  0.97986400  0.24939300  1.0
  F  F17  1  0.96004200  0.01815900  0.74998800  1.0
  F  F18  1  0.39261100  0.30459800  0.96422500  1.0
  F  F19  1  0.60625800  0.69625400  0.03446200  1.0
  F  F20  1  0.80730600  0.88580300  0.47215500  1.0
  F  F21  1  0.19317700  0.69408100  0.52986600  1.0
  F  F22  1  0.80504900  0.88604500  0.02720900  1.0
  F  F23  1  0.19236600  0.69351700  0.97931500  1.0
  F  F24  1  0.54322300  0.94422900  0.74593200  1.0
  F  F25  1  0.46065400  0.48704600  0.25385500  1.0
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