Ta3NbOs2

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-3295670 · Space group: Cmmm (#65)

Materials Project API

Basic Information

Formula

Ta3NbOs2

MP-ID

mp-3295670

Elements

Sites

Density

16.9837

g/cm³

Volume

198.71

Å³

Cell a

13.6992

Cell b

3.1928

Cell c

4.5432

α Angle

90.00

β Angle

90.00

γ Angle

90.00

Space Group

Cmmm

Point Group

mmm

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 14)

2θ	d (Å)	I	hkl
12.92	6.8496	3.7	(2,0,0)
20.60	4.3122	1.9	(1,0,1)
39.47	2.2832	25.4	(6,0,0)
39.68	2.2716	25.2	(0,0,2)
39.75	2.2675	100.0	(3,1,1)
57.21	1.6103	17.4	(6,0,2)
57.75	1.5964	8.5	(0,2,0)
71.77	1.3152	17.7	(9,1,1)
72.05	1.3107	17.6	(3,1,3)
72.21	1.3083	8.7	(6,2,0)
72.35	1.3061	8.7	(0,2,2)
84.95	1.1416	2.9	(12,0,0)
85.49	1.1358	2.9	(0,0,4)
85.69	1.1337	11.4	(6,2,2)

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Energy Properties

Formation Energy/atom

-0.38324

eV/atom

Energy/atom

-46.46325

eV/atom

Energy above Hull

0.0000

eV/atom

Uncorrected Energy

-46.4632

eV/atom

Volume/atom

16.56

Å³

c/a Ratio

0.3316

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Total Mag. Moment

0.0007

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

Ta · 0.500

Element Family

5d-TM

Solute Fraction

0.500

Interstitial Fraction

0.000

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

1.0114

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

8.4088

J/mol·K

Ω Parameter

0.8230

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

3.643%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.3202

smaller = more stable mixing

VEC

6.000

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-32.750

kJ/mol; negative = exothermic mixing

Entropy Norm

0.9206

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.518

Family

Ta-rich Multi-Component

Matrix Element

Ta · 0.500

Related Tasks

Related computation task IDs (1)

aaahfngo

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-3295670

Reference Citation

The crystal structure and related material properties of Ta3NbOs2 were obtained from the Materials Project database (MP-ID: mp-3295670, 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_Ta3NbOs2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   13.69916380
_cell_length_b   3.19283606
_cell_length_c   4.54316944
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   90.00000000
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ta3NbOs2
_chemical_formula_sum   'Ta6 Nb2 Os4'
_cell_volume   198.71452497
_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
  Ta  Ta0  1  0.58272859  0.49999900  0.25038079  1.0
  Ta  Ta1  1  0.91727141  0.49999900  0.25038079  1.0
  Ta  Ta2  1  0.25000000  0.49999900  0.24941827  1.0
  Ta  Ta3  1  0.75000000  0.49999900  0.75058173  1.0
  Ta  Ta4  1  0.08272859  0.49999900  0.74962021  1.0
  Ta  Ta5  1  0.41727141  0.49999900  0.74962021  1.0
  Nb  Nb6  1  0.75000000  0.00000000  0.25055124  1.0
  Nb  Nb7  1  0.25000000  0.00000000  0.74945076  1.0
  Os  Os8  1  0.08079425  0.00000000  0.24961136  1.0
  Os  Os9  1  0.41920575  0.00000000  0.24961136  1.0
  Os  Os10  1  0.58079425  0.00000000  0.75038864  1.0
  Os  Os11  1  0.91920575  0.00000000  0.75038864  1.0

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