TmTa5(B2Os5)2

High-Entropy Materials HEA

MP-ID: mp-3296770 · Space group: Amm2 (#38)

Materials Project API

Basic Information

Formula

TmTa5(B2Os5)2

MP-ID

mp-3296770

Elements

Sites

Density

18.1224

g/cm³

Volume

276.65

Å³

Cell a

9.5235

Cell b

9.5235

Cell c

3.0503

α Angle

90.00

β Angle

90.00

γ Angle

90.29

Space Group

Amm2

Point Group

mm2

Crystal System

Orthorhombic

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
9.29	9.5234	2.5	(0,1,0)
9.29	9.5234	2.5	(1,0,0)
13.11	6.7513	2.5	(1,-1,0)
13.18	6.7169	7.7	(1,1,0)
18.63	4.7617	1.3	(0,2,0)
18.63	4.7617	1.3	(2,0,0)
26.54	3.3585	2.6	(2,2,0)
29.28	3.0503	40.1	(0,0,1)
32.20	2.7797	12.4	(1,-1,1)
32.23	2.7773	8.3	(1,1,1)
33.86	2.6476	16.2	(2,-3,0)
33.86	2.6476	16.2	(3,-2,0)
34.02	2.6351	21.0	(2,3,0)
34.02	2.6351	21.0	(3,2,0)
34.93	2.5685	4.0	(0,2,1)
34.93	2.5685	4.0	(2,0,1)
36.20	2.4816	67.6	(1,-2,1)
36.20	2.4816	67.6	(2,-1,1)
36.25	2.4782	64.3	(1,2,1)
36.25	2.4782	64.3	(2,1,1)
37.79	2.3809	26.0	(0,4,0)
37.79	2.3808	26.0	(4,0,0)
38.95	2.3126	75.2	(1,-4,0)
38.95	2.3125	75.2	(4,-1,0)

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Energy Properties

Formation Energy/atom

-0.52640

eV/atom

Energy/atom

-42.39230

eV/atom

Energy above Hull

0.0000

eV/atom

Uncorrected Energy

-42.3923

eV/atom

Volume/atom

13.83

Å³

c/a Ratio

0.3203

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Total Mag. Moment

0.0001

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

Os · 0.500

Element Family

5d-TM

Solute Fraction

0.500

Interstitial Fraction

0.200

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

1.1648

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

9.6843

J/mol·K

Ω Parameter

1.0904

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

17.054%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.3286

smaller = more stable mixing

VEC

6.500

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-26.966

kJ/mol; negative = exothermic mixing

Entropy Norm

0.8402

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (1)

aaahfoww

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-3296770

Reference Citation

The crystal structure and related material properties of TmTa5(B2Os5)2 were obtained from the Materials Project database (MP-ID: mp-3296770, 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_TmTa5(B2Os5)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.52350254
_cell_length_b   9.52352746
_cell_length_c   3.05028205
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   90.29265157
_symmetry_Int_Tables_number   1
_chemical_formula_structural   TmTa5(B2Os5)2
_chemical_formula_sum   'Tm1 Ta5 B4 Os10'
_cell_volume   276.64885299
_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  0.82419882  0.67582675  0.00000000  1.0
  Ta  Ta1  1  0.17888563  0.32112779  0.00000000  1.0
  Ta  Ta2  1  0.32444398  0.82204882  0.00000000  1.0
  Ta  Ta3  1  0.67793348  0.17554644  0.00000000  1.0
  Ta  Ta4  1  0.50192997  0.50112939  0.00000000  1.0
  Ta  Ta5  1  0.99888053  0.99805742  0.00000000  1.0
  B  B6  1  0.62018671  0.87981091  0.00000000  1.0
  B  B7  1  0.37761022  0.12239061  0.00000000  1.0
  B  B8  1  0.12120056  0.61968120  0.00000000  1.0
  B  B9  1  0.88031875  0.37880211  0.00000000  1.0
  Os  Os10  1  0.55919225  0.72424073  0.50000000  1.0
  Os  Os11  1  0.42561906  0.28415574  0.50000000  1.0
  Os  Os12  1  0.08152470  0.78264725  0.50000000  1.0
  Os  Os13  1  0.92918530  0.21570684  0.50000000  1.0
  Os  Os14  1  0.28428552  0.57081610  0.50000000  1.0
  Os  Os15  1  0.71734724  0.41848644  0.50000000  1.0
  Os  Os16  1  0.21585006  0.07437501  0.50000000  1.0
  Os  Os17  1  0.77576064  0.94078923  0.50000000  1.0
  Os  Os18  1  0.49594942  0.00403803  0.50000000  1.0
  Os  Os19  1  0.00969716  0.49032317  0.50000000  1.0

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