Basic Information
Formula
SmNiC2
MP-ID
mp-999144
Elements
3
Sites
4
Density
7.5720
g/cm³
Volume
51.11
ų
Cell a
3.7701
Å
Cell b
3.7701
Å
Cell c
3.7547
Å
α Angle
90.00
°
β Angle
90.00
°
γ Angle
106.71
°
Space Group
Amm2
Point Group
mm2
Crystal System
Orthorhombic
Bravais Lattice
oC
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 |
|---|---|---|---|
| 23.70 | 3.7547 | 5.3 | (0,0,1) |
| 24.66 | 3.6109 | 27.3 | (1,0,0) |
| 29.53 | 3.0250 | 20.4 | (1,-1,0) |
| 34.46 | 2.6026 | 100.0 | (1,0,1) |
| 38.21 | 2.3556 | 23.6 | (1,-1,1) |
| 40.07 | 2.2501 | 16.9 | (1,1,0) |
| 47.08 | 1.9301 | 4.1 | (1,1,1) |
| 48.49 | 1.8773 | 12.1 | (0,0,2) |
| 49.53 | 1.8403 | 16.8 | (2,-1,0) |
| 50.55 | 1.8054 | 12.6 | (2,0,0) |
| 55.14 | 1.6657 | 6.5 | (1,0,2) |
| 55.62 | 1.6525 | 9.5 | (2,-1,1) |
| 56.56 | 1.6271 | 12.7 | (2,0,1) |
| 57.80 | 1.5951 | 6.5 | (1,-1,2) |
| 61.29 | 1.5125 | 1.2 | (2,-2,0) |
| 63.94 | 1.4560 | 2.8 | (2,1,0) |
| 64.66 | 1.4415 | 8.1 | (1,1,2) |
| 66.67 | 1.4029 | 7.4 | (2,-2,1) |
| 69.21 | 1.3575 | 12.3 | (2,1,1) |
| 71.83 | 1.3142 | 10.7 | (2,-1,2) |
| 72.66 | 1.3013 | 8.3 | (2,0,2) |
| 75.78 | 1.2553 | 1.0 | (3,-1,0) |
| 79.66 | 1.2036 | 3.2 | (3,0,0) |
| 80.72 | 1.1905 | 8.8 | (3,-1,1) |
Energy Properties
Formation Energy/atom
-0.28871
eV/atom
Energy/atom
-7.52888
eV/atom
Energy above Hull
0.0000
eV/atom
Uncorrected Energy
-15.8009
eV/atom
Volume/atom
12.78
ų
c/a Ratio
0.9959
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
C · 0.500
Element Family
Metalloid-Nonmetal
Solute Fraction
0.500
Interstitial Fraction
0.500
Composite Radar (normalized)
Element-Class Share
Mix Entropy ΔS/R
1.0397
HEA criterion (>1.0 = high entropy)
Mix Entropy ΔS
8.6442
J/mol·K
Ω Parameter
1.1879
Ω > 1.1 favors solid solution
Atomic Size Mismatch δr
38.313%
δr < 6.6% favors single-phase solid solution
Electronegativity Diff Δχ
0.5687
smaller = more stable mixing
VEC
6.000
valence electron concentration, affects phase stability
Mix Enthalpy ΔH_mix
-19.500
kJ/mol; negative = exothermic mixing
Entropy Norm
0.9464
SS Former
0
Phase Tendency
AM
Related Tasks
Citation & References
Materials Project Page
https://materialsproject.org/materials/mp-999144
Reference Citation
The crystal structure and related material properties of SmNiC2 were obtained from the Materials Project database (MP-ID: mp-999144, 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_SmNiC2
_symmetry_space_group_name_H-M 'P 1'
_cell_length_a 3.77009511
_cell_length_b 3.77009511
_cell_length_c 3.75467334
_cell_angle_alpha 90.00000000
_cell_angle_beta 90.00000000
_cell_angle_gamma 106.71229392
_symmetry_Int_Tables_number 1
_chemical_formula_structural SmNiC2
_chemical_formula_sum 'Sm1 Ni1 C2'
_cell_volume 51.11328998
_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
Sm Sm0 1 0.00040107 0.99959893 -0.00000000 1.0
Ni Ni1 1 0.61135756 0.38864244 0.50000000 1.0
C C2 1 0.45310424 0.84986286 0.50000000 1.0
C C3 1 0.15013714 0.54689576 0.50000000 1.0
