Tb2Tm3(CoB3)2

High-Entropy Materials HEA

MP-ID: mp-3296006 · Space group: R-3m (#166)

Materials Project API

Basic Information

Formula

Tb2Tm3(CoB3)2

MP-ID

mp-3296006

Elements

Sites

Density

8.7736

g/cm³

Volume

190.66

Å³

Cell a

5.3606

Cell b

5.3606

Cell c

8.2630

α Angle

71.07

β Angle

71.07

γ Angle

60.00

Space Group

R-3m

Point Group

-3m

Crystal System

Trigonal

Bravais Lattice

Stability

Yes

Packing Fraction

X-ray Diffraction

Diffraction Pattern

Target / Radiation

X-axis: 2θ (°); Y-axis: relative intensity; Cu Kα ; λ=1.5418 Å

Diffraction Peaks (Top 24)

2θ	d (Å)	I	hkl
23.22	3.8308	30.1	(0,0,2)
24.65	3.6111	9.8	(0,1,-1)
24.65	3.6111	4.9	(1,0,-1)
27.30	3.2665	30.2	(1,1,-1)
33.43	2.6807	58.6	(1,0,-2)
33.43	2.6803	50.0	(2,1,1)
33.43	2.6803	100.0	(1,2,1)
35.14	2.5538	1.8	(0,0,3)
35.48	2.5299	2.5	(2,1,0)
35.48	2.5299	2.5	(1,2,2)
36.79	2.4431	16.0	(1,1,-2)
36.79	2.4431	8.0	(0,1,3)
41.10	2.1961	18.8	(2,1,-1)
41.10	2.1961	37.6	(2,1,3)
41.98	2.1522	2.5	(2,2,0)
41.98	2.1522	1.2	(0,2,2)
43.69	2.0720	5.9	(2,2,3)
43.69	2.0720	2.9	(2,0,-1)
47.47	1.9154	12.2	(0,0,4)
48.00	1.8954	7.1	(2,2,-1)
48.00	1.8954	7.1	(2,0,3)
48.00	1.8954	7.1	(0,2,3)
49.29	1.8489	5.2	(2,1,-2)
49.29	1.8489	2.6	(1,2,4)

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Energy Properties

Formation Energy/atom

-0.56196

eV/atom

Energy/atom

-18.89755

eV/atom

Energy above Hull

0.0000

eV/atom

Uncorrected Energy

-18.8976

eV/atom

Volume/atom

14.67

Å³

c/a Ratio

1.5414

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Total Mag. Moment

0.0003

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.000000

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

B · 0.462

Element Family

Metalloid-Nonmetal

Solute Fraction

0.538

Interstitial Fraction

0.462

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

1.2712

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

10.5686

J/mol·K

Ω Parameter

1.6755

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

30.415%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.4004

smaller = more stable mixing

VEC

7.154

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-12.781

kJ/mol; negative = exothermic mixing

Entropy Norm

0.9170

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (1)

aaahfntm

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-3296006

Reference Citation

The crystal structure and related material properties of Tb2Tm3(CoB3)2 were obtained from the Materials Project database (MP-ID: mp-3296006, 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_Tb2Tm3(CoB3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.36056756
_cell_length_b   5.36056724
_cell_length_c   8.26300843
_cell_angle_alpha   71.07251389
_cell_angle_beta   71.07250371
_cell_angle_gamma   59.99998853
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Tb2Tm3(CoB3)2
_chemical_formula_sum   'Tb2 Tm3 Co2 B6'
_cell_volume   190.66305312
_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
  Tb  Tb0  1  0.25328614  0.25328614  0.24014157  1.0
  Tb  Tb1  1  0.74671386  0.74671386  0.75985843  1.0
  Tm  Tm2  1  0.00000000  0.00000000  0.00000000  1.0
  Tm  Tm3  1  0.41752444  0.41752444  0.74742568  1.0
  Tm  Tm4  1  0.58247556  0.58247556  0.25257432  1.0
  Co  Co5  1  0.11941774  0.11941774  0.64174579  1.0
  Co  Co6  1  0.88058226  0.88058226  0.35825421  1.0
  B  B7  1  0.16828642  0.83171358  0.50000000  1.0
  B  B8  1  0.83171358  0.50000000  0.50000000  1.0
  B  B9  1  0.50000000  0.16828642  0.50000000  1.0
  B  B10  1  0.16828642  0.50000000  0.50000000  1.0
  B  B11  1  0.50000000  0.83171358  0.50000000  1.0
  B  B12  1  0.83171358  0.16828642  0.50000000  1.0

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