Basic Information
Formula
UNi2B2C
MP-ID
mp-1025123
Elements
4
Sites
6
Density
10.0771
g/cm³
Volume
64.11
ų
Cell a
5.8253
Å
Cell b
5.8253
Å
Cell c
5.8253
Å
α Angle
145.19
°
β Angle
145.19
°
γ Angle
50.05
°
Space Group
I4/mmm
Point Group
4/mmm
Crystal System
Tetragonal
Bravais Lattice
tI
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)
| 2θ | d (Å) | I | hkl |
|---|---|---|---|
| 16.80 | 5.2784 | 16.2 | (1,1,-1) |
| 26.94 | 3.3094 | 89.9 | (1,0,0) |
| 33.97 | 2.6392 | 37.9 | (2,2,-2) |
| 36.28 | 2.4762 | 54.2 | (2,1,-1) |
| 36.46 | 2.4643 | 7.6 | (0,0,1) |
| 40.39 | 2.2329 | 100.0 | (1,1,0) |
| 50.54 | 1.8058 | 19.8 | (3,2,-2) |
| 50.68 | 1.8012 | 3.9 | (2,2,-1) |
| 51.97 | 1.7595 | 1.3 | (3,3,-3) |
| 52.52 | 1.7425 | 25.2 | (1,-1,1) |
| 55.54 | 1.6547 | 3.7 | (2,0,0) |
| 60.00 | 1.5419 | 22.0 | (1,0,1) |
| 64.03 | 1.4542 | 24.1 | (3,1,-1) |
| 65.15 | 1.4319 | 25.5 | (3,3,-2) |
| 65.50 | 1.4250 | 20.5 | (2,1,0) |
| 67.70 | 1.3841 | 7.5 | (4,3,-3) |
| 71.49 | 1.3196 | 4.9 | (4,4,-4) |
| 75.88 | 1.2539 | 12.9 | (3,2,-1) |
| 77.02 | 1.2381 | 2.0 | (4,2,-2) |
| 77.46 | 1.2322 | 8.1 | (0,0,2) |
| 79.96 | 1.1999 | 1.6 | (1,1,1) |
| 83.01 | 1.1633 | 1.8 | (4,4,-3) |
| 83.77 | 1.1547 | 4.7 | (2,-1,1) |
| 87.34 | 1.1165 | 10.7 | (2,2,0) |
Energy Properties
Formation Energy/atom
-0.37934
eV/atom
Energy/atom
-7.95291
eV/atom
Energy above Hull
0.0000
eV/atom
Uncorrected Energy
-7.9529
eV/atom
Volume/atom
10.68
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
0.6677
μB
Mag. Ordering
FM
Mag. Sites
1
Magnetization/Volume
0.010420
μB/ų
Elastic Properties
KVRH
242.745
GPa
GVRH
91.914
GPa
Young's Modulus E
244.840
GPa
Poisson Ratio ν
0.332
Pugh Ratio K/G
2.641
Vickers Hardness Est.
-
GPa
Ductility
Brittle
Anisotropy
1.161
Lame λ
181.469
GPa
Feature Analysis
Element Composition (atomic fraction)
Composition Info
Major / Matrix Element
Ni · 0.333
Element Family
3d-TM
Solute Fraction
0.667
Interstitial Fraction
0.500
Composite Radar (normalized)
Element-Class Share
Mix Entropy ΔS/R
1.3297
HEA criterion (>1.0 = high entropy)
Mix Entropy ΔS
11.0548
J/mol·K
Ω Parameter
0.6350
Ω > 1.1 favors solid solution
Atomic Size Mismatch δr
28.906%
δr < 6.6% favors single-phase solid solution
Electronegativity Diff Δχ
0.3419
smaller = more stable mixing
VEC
6.000
valence electron concentration, affects phase stability
Mix Enthalpy ΔH_mix
-38.829
kJ/mol; negative = exothermic mixing
Entropy Norm
0.9591
SS Former
0
Phase Tendency
AM
Related Tasks
Citation & References
Materials Project Page
https://materialsproject.org/materials/mp-1025123
Reference Citation
The crystal structure and related material properties of UNi2B2C were obtained from the Materials Project database (MP-ID: mp-1025123, 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_UNi2B2C
_symmetry_space_group_name_H-M 'P 1'
_cell_length_a 5.82527137
_cell_length_b 5.82527137
_cell_length_c 5.82527137
_cell_angle_alpha 145.18904858
_cell_angle_beta 145.18904858
_cell_angle_gamma 50.05288842
_symmetry_Int_Tables_number 1
_chemical_formula_structural UNi2B2C
_chemical_formula_sum 'U1 Ni2 B2 C1'
_cell_volume 64.10861219
_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
U U0 1 0.50000000 0.50000000 0.00000000 1.0
Ni Ni1 1 0.75000000 0.25000000 0.50000000 1.0
Ni Ni2 1 0.25000000 0.75000000 0.50000000 1.0
B B3 1 0.14294500 0.14294500 0.00000000 1.0
B B4 1 0.85705500 0.85705500 0.00000000 1.0
C C5 1 0.00000000 0.00000000 0.00000000 1.0
