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HEAS Data Platform · Materials Science Database

Tm2AlNiOs

High-Entropy Materials HEA

MP-ID: mp-3247361 · Space group: Imm2 (#44)

Materials Project API

Basic Information

Formula
Tm2AlNiOs
MP-ID
mp-3247361
Elements
4
Sites
5
Density
10.9056
g/cm³
Volume
93.46
ų
Cell a
5.3902
Å
Cell b
5.3902
Å
Cell c
5.3902
Å
α Angle
135.73
°
β Angle
118.17
°
γ Angle
79.15
°
Space Group
Imm2
Point Group
mm2
Crystal System
Orthorhombic
Bravais Lattice
oI
Stability
Yes
Packing Fraction
-

X-ray Diffraction

Diffraction Pattern
X-axis: 2θ (°); Y-axis: relative intensity; Cu Kα ; λ=1.5418 Å
Diffraction Peaks (Top 24)
2θd (Å)Ihkl
19.26 4.6085 44.1 (1,0,0)
24.39 3.6490 14.6 (1,0,-1)
27.23 3.2752 64.1 (0,0,1)
32.33 2.7692 4.7 (1,-1,1)
34.88 2.5721 100.0 (1,1,0)
36.26 2.4773 28.2 (2,1,-1)
39.09 2.3042 68.4 (2,0,0)
39.37 2.2884 68.0 (2,1,-2)
40.91 2.2059 52.4 (1,0,1)
40.91 2.2059 17.5 (1,-2,1)
43.57 2.0774 16.0 (2,2,-2)
44.62 2.0308 37.1 (1,-1,-1)
49.02 1.8583 8.2 (1,0,-2)
50.65 1.8022 1.2 (2,-1,1)
51.83 1.7640 1.2 (2,1,0)
52.14 1.7543 4.1 (3,1,-2)
54.61 1.6806 20.1 (1,-1,2)
56.17 1.6376 2.0 (0,0,2)
57.94 1.5918 6.2 (3,2,-2)
57.94 1.5918 6.2 (2,3,-3)
58.80 1.5705 14.2 (2,1,-3)
59.32 1.5580 6.0 (2,0,1)
59.32 1.5580 2.0 (1,-3,2)
60.16 1.5381 1.0 (3,2,-3)
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Energy Properties

Formation Energy/atom
-0.57708
eV/atom
Energy/atom
-28.96530
eV/atom
Energy above Hull
0.0000
eV/atom
Uncorrected Energy
-28.9653
eV/atom
Volume/atom
18.69
ų
c/a Ratio
1.0000

Electronic Properties

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

Magnetic Properties

Magnetic
No
Total Mag. Moment
0.0000
μB
Mag. Ordering
NM
Mag. Sites
0
Magnetization/Volume
0.000000
μB/ų

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)
Composition Info
Major / Matrix Element
Tm · 0.400
Element Family
Lanthanide
Solute Fraction
0.600
Interstitial Fraction
0.000

High-Entropy Alloy Features

Composite Radar (normalized)
Element-Class Share
Mix Entropy ΔS/R
1.3322
HEA criterion (>1.0 = high entropy)
Mix Entropy ΔS
11.0757
J/mol·K
Ω Parameter
3.3124
Ω > 1.1 favors solid solution
Atomic Size Mismatch δr
13.944%
δr < 6.6% favors single-phase solid solution
Electronegativity Diff Δχ
0.3719
smaller = more stable mixing
VEC
9.400
valence electron concentration, affects phase stability
Mix Enthalpy ΔH_mix
-6.422
kJ/mol; negative = exothermic mixing
Entropy Norm
0.9610
SS Former
0
Phase Tendency
IM

Related Tasks

Related computation task IDs (1)
aaahctun

Citation & References

Materials Project Page
https://materialsproject.org/materials/mp-3247361
Reference Citation

The crystal structure and related material properties of Tm2AlNiOs were obtained from the Materials Project database (MP-ID: mp-3247361, 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
Raw CIF Data 
# generated using pymatgen
data_Tm2AlNiOs
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.39017683
_cell_length_b   5.39017653
_cell_length_c   5.39017670
_cell_angle_alpha   135.73450681
_cell_angle_beta   118.17351649
_cell_angle_gamma   79.14894092
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Tm2AlNiOs
_chemical_formula_sum   'Tm2 Al1 Ni1 Os1'
_cell_volume   93.45653915
_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
  Tm  Tm0  1  0.69438271  0.20096741  0.49341530  1.0
  Tm  Tm1  1  0.29244790  0.79903259  0.49341530  1.0
  Al  Al2  1  0.99988511  1.00000000  0.99988511  1.0
  Ni  Ni3  1  0.73905568  0.50000000  0.23905568  1.0
  Os  Os4  1  0.27422861  0.50000000  0.77422861  1.0
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