Ta8NiSe8

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-654199 · Space group: Pnma (#62)

Materials Project API

Basic Information

Formula

Ta8NiSe8

MP-ID

mp-654199

Elements

Sites

Density

10.5240

g/cm³

Volume

1,349.36

Å³

Cell a

3.4785

Cell b

17.0336

Cell c

22.7737

α Angle

90.00

β Angle

90.00

γ Angle

90.00

Space Group

Pnma

Point Group

mmm

Crystal System

Orthorhombic

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
6.48	13.6403	18.2	(0,1,1)
7.76	11.3869	30.5	(0,0,2)
9.34	9.4664	100.0	(0,1,2)
10.39	8.5168	4.7	(0,2,0)
11.09	7.9772	1.2	(0,2,1)
12.77	6.9338	33.7	(0,1,3)
12.98	6.8202	43.0	(0,2,2)
15.56	5.6934	5.3	(0,0,4)
16.09	5.5092	6.1	(0,3,1)
16.42	5.3998	18.0	(0,1,4)
17.45	5.0812	4.0	(0,3,2)
18.75	4.7332	7.3	(0,2,4)
19.52	4.5468	3.6	(0,3,3)
20.18	4.4002	3.5	(0,1,5)
22.29	3.9886	1.5	(0,4,2)
24.02	3.7048	1.3	(0,1,6)
26.15	3.4081	2.8	(1,1,0)
26.80	3.3267	1.3	(1,0,2)
27.92	3.1956	1.4	(0,1,7)
27.98	3.1885	1.2	(1,2,1)
28.28	3.1555	1.6	(0,3,6)
28.70	3.1106	1.9	(0,4,5)
28.71	3.1092	11.7	(1,1,3)
29.39	3.0392	1.7	(0,2,7)

Get direct link

Energy Properties

Formation Energy/atom

-0.86602

eV/atom

Energy/atom

-8.43560

eV/atom

Energy above Hull

0.0019

eV/atom

Uncorrected Energy

-8.2135

eV/atom

Volume/atom

19.84

Å³

c/a Ratio

6.5471

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Total Mag. Moment

0.1847

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.000140

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

Ta · 0.471

Element Family

5d-TM

Solute Fraction

0.529

Interstitial Fraction

0.000

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

0.8761

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

7.2838

J/mol·K

Ω Parameter

4.2698

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

11.616%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.5100

smaller = more stable mixing

VEC

4.824

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-3.211

kJ/mol; negative = exothermic mixing

Entropy Norm

0.7975

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.480

Family

Ta-rich Multi-Component

Matrix Element

Ta · 0.471

Related Tasks

Related computation task IDs (2)

aaacbemc aaaczsce

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-654199

Reference Citation

The crystal structure and related material properties of Ta8NiSe8 were obtained from the Materials Project database (MP-ID: mp-654199, 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…

Style: Ball & Stick | Drag to rotate · Scroll to zoom · Right-click to pan

Raw CIF Data

# generated using pymatgen
data_Ta8NiSe8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.47845400
_cell_length_b   17.03360900
_cell_length_c   22.77369300
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   90.00000000
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ta8NiSe8
_chemical_formula_sum   'Ta32 Ni4 Se32'
_cell_volume   1349.35555202
_cell_formula_units_Z   4
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  0.75000000  0.04183500  0.95533600  1.0
  Ta  Ta1  1  0.25000000  0.54183500  0.54466400  1.0
  Ta  Ta2  1  0.75000000  0.20860000  0.33349200  1.0
  Ta  Ta3  1  0.25000000  0.05235800  0.74583600  1.0
  Ta  Ta4  1  0.25000000  0.44764200  0.24583600  1.0
  Ta  Ta5  1  0.75000000  0.45816500  0.45533600  1.0
  Ta  Ta6  1  0.75000000  0.19750700  0.55322500  1.0
  Ta  Ta7  1  0.25000000  0.15824700  0.87572100  1.0
  Ta  Ta8  1  0.25000000  0.95816500  0.04466400  1.0
  Ta  Ta9  1  0.75000000  0.81779100  0.55769100  1.0
  Ta  Ta10  1  0.75000000  0.84175300  0.12427900  1.0
  Ta  Ta11  1  0.25000000  0.70860000  0.16650800  1.0
  Ta  Ta12  1  0.75000000  0.94764200  0.25416400  1.0
  Ta  Ta13  1  0.25000000  0.69750700  0.94677500  1.0
  Ta  Ta14  1  0.25000000  0.18220900  0.44230900  1.0
  Ta  Ta15  1  0.25000000  0.06153900  0.31553000  1.0
  Ta  Ta16  1  0.75000000  0.68220900  0.05769100  1.0
  Ta  Ta17  1  0.75000000  0.66393300  0.48238800  1.0
  Ta  Ta18  1  0.25000000  0.43846100  0.81553000  1.0
  Ta  Ta19  1  0.75000000  0.93846100  0.68447000  1.0
  Ta  Ta20  1  0.75000000  0.56153900  0.18447000  1.0
  Ta  Ta21  1  0.75000000  0.65824700  0.62427900  1.0
  Ta  Ta22  1  0.75000000  0.55235800  0.75416400  1.0
  Ta  Ta23  1  0.25000000  0.79140000  0.66650800  1.0
  Ta  Ta24  1  0.25000000  0.33606700  0.51761200  1.0
  Ta  Ta25  1  0.25000000  0.34175300  0.37572100  1.0
  Ta  Ta26  1  0.25000000  0.80249300  0.44677500  1.0
  Ta  Ta27  1  0.75000000  0.29140000  0.83349200  1.0
  Ta  Ta28  1  0.25000000  0.31779100  0.94230900  1.0
  Ta  Ta29  1  0.25000000  0.16393300  0.01761200  1.0
  Ta  Ta30  1  0.75000000  0.30249300  0.05322500  1.0
  Ta  Ta31  1  0.75000000  0.83606700  0.98238800  1.0
  Ni  Ni32  1  0.25000000  0.70927200  0.55435000  1.0
  Ni  Ni33  1  0.75000000  0.29072800  0.44565000  1.0
  Ni  Ni34  1  0.25000000  0.79072800  0.05435000  1.0
  Ni  Ni35  1  0.75000000  0.20927200  0.94565000  1.0
  Se  Se36  1  0.75000000  0.09036900  0.66544300  1.0
  Se  Se37  1  0.75000000  0.71304200  0.73134000  1.0
  Se  Se38  1  0.75000000  0.39566700  0.73690300  1.0
  Se  Se39  1  0.25000000  0.93159600  0.92638500  1.0
  Se  Se40  1  0.25000000  0.95016300  0.16235800  1.0
  Se  Se41  1  0.25000000  0.59036900  0.83455700  1.0
  Se  Se42  1  0.25000000  0.90963100  0.33455700  1.0
  Se  Se43  1  0.75000000  0.40963100  0.16544300  1.0
  Se  Se44  1  0.25000000  0.41222900  0.03113400  1.0
  Se  Se45  1  0.25000000  0.54983700  0.66235800  1.0
  Se  Se46  1  0.25000000  0.57560400  0.09782100  1.0
  Se  Se47  1  0.75000000  0.78695800  0.23134000  1.0
  Se  Se48  1  0.25000000  0.60433300  0.26309700  1.0
  Se  Se49  1  0.25000000  0.28695800  0.26866000  1.0
  Se  Se50  1  0.25000000  0.89566700  0.76309700  1.0
  Se  Se51  1  0.75000000  0.91222900  0.46886600  1.0
  Se  Se52  1  0.75000000  0.58777100  0.96886600  1.0
  Se  Se53  1  0.75000000  0.10433300  0.23690300  1.0
  Se  Se54  1  0.75000000  0.45016300  0.33764200  1.0
  Se  Se55  1  0.25000000  0.23187800  0.12037600  1.0
  Se  Se56  1  0.25000000  0.26812200  0.62037600  1.0
  Se  Se57  1  0.75000000  0.04983700  0.83764200  1.0
  Se  Se58  1  0.25000000  0.92439600  0.59782100  1.0
  Se  Se59  1  0.25000000  0.56840400  0.42638500  1.0
  Se  Se60  1  0.25000000  0.21304200  0.76866000  1.0
  Se  Se61  1  0.75000000  0.43159600  0.57361500  1.0
  Se  Se62  1  0.75000000  0.42439600  0.90217900  1.0
  Se  Se63  1  0.25000000  0.08777100  0.53113400  1.0
  Se  Se64  1  0.75000000  0.06840400  0.07361500  1.0
  Se  Se65  1  0.75000000  0.73187800  0.37962400  1.0
  Se  Se66  1  0.75000000  0.76812200  0.87962400  1.0
  Se  Se67  1  0.75000000  0.07560400  0.40217900  1.0

Get direct link