Ta2Se8I

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-30531 · Space group: I422 (#97)

Materials Project API

Basic Information

Formula

Ta2Se8I

MP-ID

mp-30531

Elements

Sites

Density

5.9726

g/cm³

Volume

623.05

Å³

Cell a

9.4956

Cell b

9.4956

Cell c

9.4956

α Angle

117.92

β Angle

117.92

γ Angle

93.64

Space Group

I422

Point Group

422

Crystal System

Tetragonal

Bravais Lattice

Stability

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
11.31	7.8206	1.7	(1,0,-1)
12.79	6.9240	100.0	(1,-1,0)
18.12	4.8960	41.1	(1,-1,1)
18.73	4.7382	1.2	(1,1,-2)
21.41	4.1499	16.8	(2,-1,-1)
22.44	3.9616	1.7	(2,1,-2)
25.73	3.4620	6.3	(2,-2,0)
27.45	3.2490	7.4	(2,2,-2)
28.99	3.0797	18.6	(3,0,-2)
30.39	2.9413	12.7	(2,2,-3)
32.02	2.7953	26.1	(3,-1,-2)
33.09	2.7072	17.2	(3,1,-3)
33.72	2.6584	4.3	(3,-2,-1)
36.71	2.4480	10.6	(2,-2,2)
37.98	2.3691	23.7	(2,2,-4)
38.54	2.3362	3.7	(3,-2,-2)
39.03	2.3080	3.1	(3,-3,0)
39.15	2.3010	5.0	(4,-1,-2)
40.23	2.2415	69.4	(4,0,-3)
41.23	2.1896	25.7	(3,-3,1)
43.45	2.0825	3.4	(4,-1,-3)
43.62	2.0749	12.4	(4,-2,-2)
46.45	1.9552	4.1	(4,0,-4)
46.92	1.9365	1.4	(4,-3,-1)

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Energy Properties

Formation Energy/atom

-0.55980

eV/atom

Energy/atom

-5.39845

eV/atom

Energy above Hull

0.1964

eV/atom

Uncorrected Energy

-5.3640

eV/atom

Volume/atom

28.32

Å³

c/a Ratio

1.0000

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Total Mag. Moment

0.0004

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

Se · 0.727

Element Family

Metalloid-Nonmetal

Solute Fraction

0.273

Interstitial Fraction

0.000

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

0.7595

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

6.3149

J/mol·K

Ω Parameter

0.0000

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

10.577%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.4109

smaller = more stable mixing

VEC

4.273

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

0.000

kJ/mol; negative = exothermic mixing

Entropy Norm

0.6914

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.506

Family

Se-rich Multi-Component

Matrix Element

Se · 0.727

Related Tasks

Related computation task IDs (5)

aaadopih aaadwejz aaaegdwa aaaepozg aaafbigy

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-30531

Reference Citation

The crystal structure and related material properties of Ta2Se8I were obtained from the Materials Project database (MP-ID: mp-30531, 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

Loading 3D structure…

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Raw CIF Data

# generated using pymatgen
data_Ta2Se8I
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.49554854
_cell_length_b   9.49554854
_cell_length_c   9.49554854
_cell_angle_alpha   117.92335404
_cell_angle_beta   117.92335404
_cell_angle_gamma   93.63613831
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ta2Se8I
_chemical_formula_sum   'Ta4 Se16 I2'
_cell_volume   623.04933948
_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  0.25000000  0.75000000  0.50000000  1.0
  Ta  Ta1  1  0.75000000  0.25000000  0.50000000  1.0
  Ta  Ta2  1  0.00000000  0.50000000  0.50000000  1.0
  Ta  Ta3  1  0.50000000  0.00000000  0.50000000  1.0
  Se  Se4  1  0.34013300  0.67567000  0.75545600  1.0
  Se  Se5  1  0.92021400  0.58467700  0.24454400  1.0
  Se  Se6  1  0.32433000  0.65986700  0.24454400  1.0
  Se  Se7  1  0.58467700  0.34013300  0.66446200  1.0
  Se  Se8  1  0.67567000  0.92021400  0.33553800  1.0
  Se  Se9  1  0.65986700  0.41532300  0.33553800  1.0
  Se  Se10  1  0.19552100  0.99845100  0.43384000  1.0
  Se  Se11  1  0.99845100  0.56461100  0.80293000  1.0
  Se  Se12  1  0.76168100  0.19552100  0.19707000  1.0
  Se  Se13  1  0.43538900  0.00154900  0.19707000  1.0
  Se  Se14  1  0.80447900  0.23831900  0.80293000  1.0
  Se  Se15  1  0.56461100  0.76168100  0.56616000  1.0
  Se  Se16  1  0.00154900  0.80447900  0.56616000  1.0
  Se  Se17  1  0.23831900  0.43538900  0.43384000  1.0
  Se  Se18  1  0.41532300  0.07978600  0.75545600  1.0
  Se  Se19  1  0.07978600  0.32433000  0.66446200  1.0
  I  I20  1  0.84554100  0.84554100  0.00000000  1.0
  I  I21  1  0.15445900  0.15445900  0.00000000  1.0

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