Navigation

HEAS Data Platform · Materials Science Database

Tl(FeSe)2

High-Entropy Materials HEA Traditional Materials TRA Elasticity Data ELA

MP-ID: mp-3021 · Space group: I4/mmm (#139)

Basic Information

Formula
Tl(FeSe)2
MP-ID
mp-3021
Elements
3
Sites
5
Density
7.4614
g/cm³
Volume
105.49
ų
Cell a
8.1275
Å
Cell b
8.1275
Å
Cell c
8.1275
Å
α Angle
153.67
°
β Angle
153.67
°
γ Angle
37.58
°
Space Group
I4/mmm
Point Group
4/mmm
Crystal System
Tetragonal
Bravais Lattice
Tetragonal I
Stability
No
Packing Fraction
0.7400

X-ray Diffraction

Diffraction Pattern
X-axis: 2θ (°); Y-axis: relative intensity; CuKa ; λ=1.5406 Å
Diffraction Peaks (Top 24)
2θd (Å)Ihkl
11.50 7.6942 2.6 (1,1,-1)
23.12 3.8471 12.0 (2,2,-2)
24.73 3.6000 12.9 (1,0,0)
29.76 3.0022 100.0 (2,1,-1)
34.25 2.6182 16.9 (0,0,1)
34.99 2.5647 4.5 (3,3,-3)
36.24 2.4786 40.3 (1,1,0)
38.02 2.3668 24.6 (3,2,-2)
41.73 2.1645 1.2 (2,2,-1)
47.25 1.9236 10.3 (4,4,-4)
49.22 1.8514 23.7 (1,-1,1)
49.77 1.8322 34.9 (3,3,-2)
55.05 1.6682 4.5 (3,1,-1)
55.84 1.6464 3.1 (1,0,1)
58.58 1.5758 29.6 (2,1,0)
59.55 1.5523 6.6 (5,4,-4)
59.65 1.5502 4.3 (4,4,-3)
61.80 1.5011 3.8 (4,2,-2)
63.83 1.4582 11.0 (3,2,-1)
70.61 1.3339 12.1 (5,3,-3)
71.06 1.3267 2.1 (5,5,-4)
72.16 1.3091 7.4 (0,0,2)
72.19 1.3087 8.0 (6,5,-5)
73.91 1.2824 1.2 (6,6,-6)
Get direct link

Energy Properties

Formation Energy/atom
-0.41462
eV/atom
Energy/atom
-5.67529
eV/atom
Energy above Hull
0.0317
eV/atom
Uncorrected Energy
-5.4865
eV/atom
Volume/atom
21.10
ų
c/a Ratio
1.0000

Electronic Properties

Metallic
Metal
Band Gap
0
eV
Direct Gap
No
CBM
N/A
eV

Magnetic Properties

Magnetic
Yes
Total Mag. Moment
5.7536
μB
Mag. Ordering
FM
Mag. Sites
2
Magnetization/Volume
0.054540
μB/ų

Elastic Properties

KVRH
38.004
GPa
GVRH
22.879
GPa
Young's Modulus E
57.165
GPa
Poisson Ratio ν
0.249
Pugh Ratio K/G
1.661
Vickers Hardness Est.
3.894
GPa
Ductility
Ductile
Anisotropy
0.473
Lame λ
22.751
GPa

Feature Analysis

Composition Overview

Element Composition (atomic fraction)
Composition Info
Major / Matrix Element
Fe · 0.400
Element Family
3d-TM
Solute Fraction
0.600
Interstitial Fraction
0.000

High-Entropy Alloy Features

Composite Radar (normalized)
Element-Class Share
Mix Entropy ΔS/R
1.0549
HEA criterion (>1.0 = high entropy)
Mix Entropy ΔS
8.7706
J/mol·K
Ω Parameter
1.1070
Ω > 1.1 favors solid solution
Atomic Size Mismatch δr
15.646%
δr < 6.6% favors single-phase solid solution
Electronegativity Diff Δχ
0.3945
smaller = more stable mixing
VEC
5.400
valence electron concentration, affects phase stability
Mix Enthalpy ΔH_mix
8.219
kJ/mol; negative = exothermic mixing
Entropy Norm
0.9602
SS Former
0
Phase Tendency
IM

Traditional Material Features

ROM Blended-Feature Radar
Rating & Classification
Tier
B
Score
0.532
Family
Fe-rich Multi-Component
Matrix Element
Fe · 0.400

Elasticity Features

Elastic Modulus Comparison (GPa)
Elastic Features
Elastic Anisotropy AU
0.4730
Homogeneous Poisson ν
0.2490
Debye Temperature
239.7
K
Sound Velocity
1,943.9
m/s
Homogeneity
0.2490

Related Tasks

Citation & References

Materials Project Page
https://materialsproject.org/materials/mp-3021
Reference Citation

The crystal structure and related material properties of Tl(FeSe)2 were obtained from the Materials Project database (MP-ID: mp-3021, 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

BibTeX
@article{Horton2025,
  author  = {Horton, Matthew K. and Huck, Patrick and Yang, Ruo Xi and Munro, Jason M. and Dwaraknath, Shyam and Ganose, Alex M. and Kingsbury, Ryan S. and Wen, Mingjian and Shen, Jimmy X. and Mathis, Tyler S. and Kaplan, Aaron D. and Berket, Karlo and Riebesell, Janosh and George, Janine and Rosen, Andrew S. and Spotte-Smith, Evan W. C. and McDermott, Matthew J. and Cohen, Orion A. and Dunn, Alex and Kuner, Matthew C. and Rignanese, Gian-Marco and Petretto, Guido and Waroquiers, David and Griffin, Sinead M. and Neaton, Jeffrey B. and Chrzan, Daryl C. and Asta, Mark and Hautier, Geoffroy and Cholia, Shreyas and Ceder, Gerbrand and Ong, Shyue Ping and Jain, Anubhav and Persson, Kristin A.},
  title   = {Accelerated data-driven materials science with the Materials Project},
  journal = {Nature Materials},
  year    = {2025},
  volume  = {24},
  number  = {10},
  pages   = {1522--1532},
  month   = {oct},
  doi     = {10.1038/s41563-025-02272-0},
  issn    = {1476-4660},
  url     = {https://doi.org/10.1038/s41563-025-02272-0},
  abstract = {The Materials Project was launched formally in 2011 to drive materials discovery forwards through high-throughput computation and open data. More than a decade later, the Materials Project has become an indispensable tool used by more than 600,000 materials researchers around the world. This Perspective describes how the Materials Project, as a data platform and a software ecosystem, has helped to shape research in data-driven materials science. We cover how sustainable software and computational methods have accelerated materials design while becoming more open source and collaborative in nature. Next, we present cases where the Materials Project was used to understand and discover functional materials. We then describe our efforts to meet the needs of an expanding user base, through technical infrastructure updates ranging from data architecture and cloud resources to interactive web applications. Finally, we discuss opportunities to better aid the research community, with the vision that more accessible and easy-to-understand materials data will result in democratized materials knowledge and an increasingly collaborative community.}
}

3D Crystal Structure Rendering

Loading 3D structure…

Style: Ball & Stick
Raw CIF Data
# generated using pymatgen
data_Tl(FeSe)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.12749565
_cell_length_b   8.12749565
_cell_length_c   8.12749565
_cell_angle_alpha   153.66624577
_cell_angle_beta   153.66624577
_cell_angle_gamma   37.58489183
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Tl(FeSe)2
_chemical_formula_sum   'Tl1 Fe2 Se2'
_cell_volume   105.48738081
_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
  Tl  Tl0  1  0.00000000  0.00000000  0.00000000  1.0
  Fe  Fe1  1  0.75000000  0.25000000  0.50000000  1.0
  Fe  Fe2  1  0.25000000  0.75000000  0.50000000  1.0
  Se  Se3  1  0.64269500  0.64269500  0.00000000  1.0
  Se  Se4  1  0.35730500  0.35730500  0.00000000  1.0
Get direct link