Tm3Co9(SiB2)2
High-Entropy Materials HEAMP-ID: mp-3296698 · Space group: P6/mmm (#191)
Basic Information
Formula
Tm3Co9(SiB2)2
MP-ID
mp-3296698
Elements
4
Sites
18
Density
9.2763
g/cm³
Volume
203.46
ų
Cell a
5.0409
Å
Cell b
5.0409
Å
Cell c
9.2456
Å
α Angle
90.00
°
β Angle
90.00
°
γ Angle
120.00
°
Space Group
P6/mmm
Point Group
6/mmm
Crystal System
Hexagonal
Bravais Lattice
hP
Stability
Yes
Packing Fraction
0.7405
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 |
|---|---|---|---|
| 9.57 | 9.2456 | 1.1 | (0,0,0,1) |
| 20.34 | 4.3656 | 35.5 | (1,0,-1,0) |
| 35.62 | 2.5205 | 7.0 | (1,-2,1,0) |
| 35.62 | 2.5205 | 14.0 | (2,-1,-1,0) |
| 35.66 | 2.5177 | 100.0 | (1,0,-1,3) |
| 38.97 | 2.3114 | 2.3 | (0,0,0,4) |
| 40.78 | 2.2129 | 1.1 | (2,-1,-1,2) |
| 41.36 | 2.1828 | 87.3 | (2,0,-2,0) |
| 44.34 | 2.0428 | 2.7 | (1,0,-1,4) |
| 46.55 | 1.9511 | 22.7 | (1,-2,1,3) |
| 46.55 | 1.9511 | 45.4 | (2,-1,-1,3) |
| 49.28 | 1.8491 | 1.3 | (0,0,0,5) |
| 55.71 | 1.6500 | 3.9 | (3,-2,-1,0) |
| 55.71 | 1.6500 | 1.9 | (3,-1,-2,0) |
| 58.13 | 1.5870 | 2.5 | (2,0,-2,4) |
| 60.04 | 1.5409 | 7.9 | (0,0,0,6) |
| 63.98 | 1.4552 | 1.3 | (3,-3,0,0) |
| 63.98 | 1.4552 | 1.3 | (0,3,-3,0) |
| 63.98 | 1.4552 | 1.3 | (3,0,-3,0) |
| 64.01 | 1.4547 | 6.0 | (2,-3,1,3) |
| 64.01 | 1.4547 | 18.0 | (3,-2,-1,3) |
| 64.01 | 1.4547 | 12.0 | (3,-1,-2,3) |
| 64.08 | 1.4531 | 5.7 | (1,0,-1,6) |
| 66.24 | 1.4109 | 1.0 | (2,-2,0,5) |
Energy Properties
Formation Energy/atom
-0.53980
eV/atom
Energy/atom
-15.61780
eV/atom
Energy above Hull
0.0000
eV/atom
Uncorrected Energy
-15.6178
eV/atom
Volume/atom
11.30
ų
c/a Ratio
1.8341
Electronic Properties
Metallic
Metal
Band Gap
0
eV
Direct Gap
No
CBM
N/A
eV
Magnetic Properties
Magnetic
No
Total Mag. Moment
0.0296
μB
Mag. Ordering
NM
Mag. Sites
0
Magnetization/Volume
0.000150
μB/ų
Elastic Properties
Elastic data not available
Feature Analysis
Composition Overview
Element Composition (atomic fraction)
Composition Info
Major / Matrix Element
Co · 0.500
Element Family
3d-TM
Solute Fraction
0.500
Interstitial Fraction
0.333
High-Entropy Alloy Features
Composite Radar (normalized)
Element-Class Share
Mix Entropy ΔS/R
1.2236
HEA criterion (>1.0 = high entropy)
Mix Entropy ΔS
10.1728
J/mol·K
Ω Parameter
0.6680
Ω > 1.1 favors solid solution
Atomic Size Mismatch δr
21.160%
δr < 6.6% favors single-phase solid solution
Electronegativity Diff Δχ
0.2595
smaller = more stable mixing
VEC
7.778
valence electron concentration, affects phase stability
Mix Enthalpy ΔH_mix
-28.879
kJ/mol; negative = exothermic mixing
Entropy Norm
0.8826
SS Former
0
Phase Tendency
AM
Related Tasks
Related computation task IDs (1)
Citation & References
Materials Project Page
https://materialsproject.org/materials/mp-3296698
Reference Citation
The crystal structure and related material properties of Tm3Co9(SiB2)2 were obtained from the Materials Project database (MP-ID: mp-3296698, 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_Tm3Co9(SiB2)2
_symmetry_space_group_name_H-M 'P 1'
_cell_length_a 5.04092459
_cell_length_b 5.04092544
_cell_length_c 9.24564394
_cell_angle_alpha 90.00000000
_cell_angle_beta 90.00000000
_cell_angle_gamma 120.00000724
_symmetry_Int_Tables_number 1
_chemical_formula_structural Tm3Co9(SiB2)2
_chemical_formula_sum 'Tm3 Co9 Si2 B4'
_cell_volume 203.46430964
_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
Tm Tm0 1 0.00000000 0.00000000 0.00000000 1.0
Tm Tm1 1 0.00000000 0.00000000 0.66167489 1.0
Tm Tm2 1 0.00000000 0.00000000 0.33832511 1.0
Co Co3 1 0.50000000 0.50000000 0.50000000 1.0
Co Co4 1 0.50000000 0.00000000 0.50000000 1.0
Co Co5 1 0.00000000 0.50000000 0.50000000 1.0
Co Co6 1 0.50000000 0.50000000 0.80408520 1.0
Co Co7 1 0.50000000 0.00000000 0.80408520 1.0
Co Co8 1 0.00000000 0.50000000 0.80408520 1.0
Co Co9 1 0.50000000 0.50000000 0.19591480 1.0
Co Co10 1 0.50000000 0.00000000 0.19591480 1.0
Co Co11 1 0.00000000 0.50000000 0.19591480 1.0
Si Si12 1 0.66666700 0.33333300 0.00000000 1.0
Si Si13 1 0.33333300 0.66666700 0.00000000 1.0
B B14 1 0.66666700 0.33333300 0.65501893 1.0
B B15 1 0.33333300 0.66666700 0.65501893 1.0
B B16 1 0.33333300 0.66666700 0.34498107 1.0
B B17 1 0.66666700 0.33333300 0.34498107 1.0
