K2TaCuSe4

High-Entropy Materials HEA

MP-ID: mp-666297 · Space group: P1 (#1)

Materials Project API

Basic Information

Formula

K2TaCuSe4

MP-ID

mp-666297

Elements

Sites

Density

4.3506

g/cm³

Volume

487.43

Å³

Cell a

14.0365

Cell b

12.5542

Cell c

7.4887

α Angle

84.91

β Angle

62.98

γ Angle

32.10

Space Group

Point Group

Crystal System

Triclinic

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
14.50	6.1089	56.5	(2,2,0)
14.73	6.0147	100.0	(0,1,-1)
17.03	5.2051	8.1	(1,1,1)
19.91	4.4584	28.6	(2,2,1)
25.00	3.5624	25.3	(2,0,1)
25.39	3.5086	29.9	(2,3,-1)
27.07	3.2934	20.1	(0,2,-1)
29.24	3.0545	2.6	(4,4,0)
29.71	3.0073	10.0	(0,2,-2)
30.62	2.9198	11.2	(4,4,1)
30.84	2.8990	53.9	(1,2,-2)
33.65	2.6637	10.9	(1,1,2)
36.22	2.4802	2.9	(3,0,2)
36.81	2.4416	14.5	(3,3,2)
38.21	2.3551	33.0	(3,4,1)
39.10	2.3038	4.4	(4,5,-1)
39.37	2.2884	23.2	(2,4,-2)
40.63	2.2208	4.2	(0,3,-2)
41.42	2.1797	34.5	(3,2,3)
44.49	2.0363	1.2	(6,6,0)
44.67	2.0288	1.1	(1,3,-3)
45.17	2.0075	12.0	(5,5,2)
45.23	2.0049	17.1	(0,3,-3)
46.68	1.9460	4.8	(5,4,3)

Get direct link

Energy Properties

Formation Energy/atom

-1.16987

eV/atom

Energy/atom

-5.19644

eV/atom

Energy above Hull

0.0127

eV/atom

Uncorrected Energy

-4.9604

eV/atom

Volume/atom

30.46

Å³

c/a Ratio

0.5335

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Total Mag. Moment

0.0002

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 · 0.500

Element Family

Metalloid-Nonmetal

Solute Fraction

0.500

Interstitial Fraction

0.000

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

1.2130

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

10.0849

J/mol·K

Ω Parameter

73.5904

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

29.620%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.7231

smaller = more stable mixing

VEC

4.250

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

0.125

kJ/mol; negative = exothermic mixing

Entropy Norm

0.8750

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (1)

aaablxqv

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-666297

Reference Citation

The crystal structure and related material properties of K2TaCuSe4 were obtained from the Materials Project database (MP-ID: mp-666297, 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_K2TaCuSe4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   14.03645240
_cell_length_b   12.55419607
_cell_length_c   7.48871514
_cell_angle_alpha   84.91470317
_cell_angle_beta   62.98391137
_cell_angle_gamma   32.10138546
_symmetry_Int_Tables_number   1
_chemical_formula_structural   K2TaCuSe4
_chemical_formula_sum   'K4 Ta2 Cu2 Se8'
_cell_volume   487.42512878
_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
  K  K0  1  0.32684500  0.31295400  0.67092900  1.0
  K  K1  1  0.67924800  0.67936700  0.31417800  1.0
  K  K2  1  0.92680600  0.92850700  0.57283500  1.0
  K  K3  1  0.56350400  0.57791200  0.93028100  1.0
  Ta  Ta4  1  0.49483300  0.50548500  0.49811100  1.0
  Ta  Ta5  1  0.75580600  0.74690800  0.74938500  1.0
  Cu  Cu6  1  0.25944900  0.24087200  0.24250900  1.0
  Cu  Cu7  1  0.99073900  0.00922100  0.00535100  1.0
  Se  Se8  1  0.95040200  0.65959800  0.34599500  1.0
  Se  Se9  1  0.22098300  0.89326800  0.57738300  1.0
  Se  Se10  1  0.90346500  0.20707000  0.29757900  1.0
  Se  Se11  1  0.59001300  0.29803000  0.20222300  1.0
  Se  Se12  1  0.34482300  0.04026500  0.94431800  1.0
  Se  Se13  1  0.67269100  0.94386200  0.03073800  1.0
  Se  Se14  1  0.30043200  0.58326100  0.89848100  1.0
  Se  Se15  1  0.03228400  0.35385100  0.66489800  1.0

Get direct link