Basic Information
Formula
Tm2NiAs2
MP-ID
mp-11581
Elements
3
Sites
10
Density
9.2060
g/cm³
Volume
197.12
ų
Cell a
4.0429
Å
Cell b
4.0429
Å
Cell c
13.9253
Å
α Angle
90.00
°
β Angle
90.00
°
γ Angle
120.00
°
Space Group
P6_3/mmc
Point Group
6/mmm
Crystal System
Hexagonal
Bravais Lattice
hP
Stability
No
Packing Fraction
0.7405
X-ray Diffraction
Diffraction Pattern
X-axis: 2θ (°); Y-axis: relative intensity; Cu Kα ; λ=1.5418 Å
Diffraction Peaks (Top 24)
| 2θ | d (Å) | I | hkl |
|---|---|---|---|
| 12.71 | 6.9627 | 3.1 | (0,0,0,2) |
| 25.44 | 3.5013 | 5.7 | (1,0,-1,0) |
| 25.59 | 3.4813 | 5.5 | (0,0,0,4) |
| 26.25 | 3.3956 | 14.9 | (0,1,-1,1) |
| 26.25 | 3.3956 | 29.8 | (1,0,-1,1) |
| 28.54 | 3.1280 | 2.8 | (1,0,-1,2) |
| 32.02 | 2.7952 | 49.1 | (0,1,-1,3) |
| 32.02 | 2.7952 | 98.2 | (1,0,-1,3) |
| 36.39 | 2.4687 | 84.4 | (1,0,-1,4) |
| 38.80 | 2.3209 | 4.1 | (0,0,0,6) |
| 41.43 | 2.1796 | 13.1 | (0,1,-1,5) |
| 41.43 | 2.1796 | 26.1 | (1,0,-1,5) |
| 44.84 | 2.0215 | 100.0 | (2,-1,-1,0) |
| 46.97 | 1.9345 | 5.4 | (1,0,-1,6) |
| 52.34 | 1.7481 | 3.6 | (1,1,-2,4) |
| 52.34 | 1.7481 | 1.8 | (2,-1,-1,4) |
| 52.58 | 1.7407 | 19.1 | (0,0,0,8) |
| 52.70 | 1.7370 | 2.3 | (0,2,-2,1) |
| 52.70 | 1.7370 | 4.6 | (2,0,-2,1) |
| 52.94 | 1.7296 | 15.2 | (1,0,-1,7) |
| 56.15 | 1.6380 | 10.0 | (0,2,-2,3) |
| 56.15 | 1.6380 | 20.0 | (2,0,-2,3) |
| 59.06 | 1.5640 | 6.8 | (0,2,-2,4) |
| 59.06 | 1.5640 | 13.6 | (2,0,-2,4) |
Energy Properties
Formation Energy/atom
-1.20944
eV/atom
Energy/atom
-6.02652
eV/atom
Energy above Hull
0.0081
eV/atom
Uncorrected Energy
-23.7168
eV/atom
Volume/atom
19.71
ų
c/a Ratio
3.4444
Electronic Properties
Metallic
Metal
Band Gap
0
eV
Direct Gap
No
CBM
N/A
eV
Magnetic Properties
Magnetic
Yes
Total Mag. Moment
0.0000
μB
Mag. Ordering
Unknown
Mag. Sites
0
Magnetization/Volume
0.000000
μB/ų
Elastic Properties
Elastic data not available
Feature Analysis
Element Composition (atomic fraction)
Composition Info
Major / Matrix Element
Tm · 0.400
Element Family
Lanthanide
Solute Fraction
0.600
Interstitial Fraction
0.000
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
0.0000
Ω > 1.1 favors solid solution
Atomic Size Mismatch δr
19.969%
δr < 6.6% favors single-phase solid solution
Electronegativity Diff Δχ
0.4232
smaller = more stable mixing
VEC
8.400
valence electron concentration, affects phase stability
Mix Enthalpy ΔH_mix
0.000
kJ/mol; negative = exothermic mixing
Entropy Norm
0.9602
SS Former
0
Phase Tendency
IM
Related Tasks
Citation & References
Materials Project Page
https://materialsproject.org/materials/mp-11581
Reference Citation
The crystal structure and related material properties of Tm2NiAs2 were obtained from the Materials Project database (MP-ID: mp-11581, 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
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Raw CIF Data
# generated using pymatgen
data_Tm2NiAs2
_symmetry_space_group_name_H-M 'P 1'
_cell_length_a 4.04289410
_cell_length_b 4.04289479
_cell_length_c 13.92534429
_cell_angle_alpha 90.00000000
_cell_angle_beta 90.00000000
_cell_angle_gamma 119.99999437
_symmetry_Int_Tables_number 1
_chemical_formula_structural Tm2NiAs2
_chemical_formula_sum 'Tm4 Ni2 As4'
_cell_volume 197.11578449
_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
Tm Tm0 1 0.33333300 0.66666700 0.88243353 1.0
Tm Tm1 1 0.66666700 0.33333300 0.38243353 1.0
Tm Tm2 1 0.66666700 0.33333300 0.11756647 1.0
Tm Tm3 1 0.33333300 0.66666700 0.61756647 1.0
Ni Ni4 1 -0.00000000 -0.00000000 0.75000000 1.0
Ni Ni5 1 -0.00000000 0.00000000 0.25000000 1.0
As As6 1 0.00000000 -0.00000000 -0.00000000 1.0
As As7 1 0.33333300 0.66666700 0.25000000 1.0
As As8 1 0.66666700 0.33333300 0.75000000 1.0
As As9 1 0.00000000 -0.00000000 0.50000000 1.0
