Basic Information
Formula
ErCuSi
MP-ID
mp-8122
Elements
3
Sites
6
Density
8.0154
g/cm³
Volume
107.27
ų
Cell a
4.0907
Å
Cell b
4.0907
Å
Cell c
7.4018
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
Yes
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 19)
| 2θ | d (Å) | I | hkl |
|---|---|---|---|
| 24.05 | 3.7009 | 4.0 | (0,0,0,2) |
| 25.14 | 3.5427 | 34.0 | (1,0,-1,0) |
| 27.92 | 3.1955 | 4.8 | (1,0,-1,1) |
| 35.06 | 2.5592 | 100.0 | (1,0,-1,2) |
| 44.28 | 2.0454 | 39.0 | (2,-1,-1,0) |
| 44.76 | 2.0247 | 1.4 | (1,0,-1,3) |
| 49.24 | 1.8505 | 9.5 | (0,0,0,4) |
| 51.02 | 1.7902 | 3.7 | (2,-1,-1,2) |
| 51.60 | 1.7713 | 3.4 | (2,0,-2,0) |
| 51.60 | 1.7713 | 1.7 | (0,2,-2,0) |
| 56.07 | 1.6402 | 8.0 | (1,0,-1,4) |
| 57.70 | 1.5978 | 23.6 | (2,0,-2,2) |
| 68.36 | 1.3722 | 20.9 | (2,-1,-1,4) |
| 70.30 | 1.3390 | 2.8 | (3,-1,-2,0) |
| 70.30 | 1.3390 | 1.4 | (1,2,-3,0) |
| 74.10 | 1.2796 | 3.6 | (2,0,-2,4) |
| 75.51 | 1.2591 | 21.2 | (3,-1,-2,2) |
| 81.51 | 1.1809 | 6.4 | (3,0,-3,0) |
| 82.86 | 1.1650 | 8.3 | (1,0,-1,6) |
Energy Properties
Formation Energy/atom
-0.72760
eV/atom
Energy/atom
-18.57627
eV/atom
Energy above Hull
0.0000
eV/atom
Uncorrected Energy
-18.5763
eV/atom
Volume/atom
17.88
ų
c/a Ratio
1.8094
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
KVRH
97.809
GPa
GVRH
63.774
GPa
Young's Modulus E
157.164
GPa
Poisson Ratio ν
0.232
Pugh Ratio K/G
1.534
Vickers Hardness Est.
-
GPa
Ductility
Ductile
Anisotropy
0.504
Lame λ
55.293
GPa
Feature Analysis
Element Composition (atomic fraction)
Composition Info
Major / Matrix Element
Er · 0.333
Element Family
Lanthanide
Solute Fraction
0.667
Interstitial Fraction
0.333
Composite Radar (normalized)
Element-Class Share
Mix Entropy ΔS/R
1.0986
HEA criterion (>1.0 = high entropy)
Mix Entropy ΔS
9.1339
J/mol·K
Ω Parameter
1.7476
Ω > 1.1 favors solid solution
Atomic Size Mismatch δr
17.966%
δr < 6.6% favors single-phase solid solution
Electronegativity Diff Δχ
0.3111
smaller = more stable mixing
VEC
9.000
valence electron concentration, affects phase stability
Mix Enthalpy ΔH_mix
-8.444
kJ/mol; negative = exothermic mixing
Entropy Norm
1.0000
SS Former
0
Phase Tendency
IM
Related Tasks
Citation & References
Materials Project Page
https://materialsproject.org/materials/mp-8122
Reference Citation
The crystal structure and related material properties of ErCuSi were obtained from the Materials Project database (MP-ID: mp-8122, 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_ErCuSi
_symmetry_space_group_name_H-M 'P 1'
_cell_length_a 4.09073350
_cell_length_b 4.09073341
_cell_length_c 7.40181632
_cell_angle_alpha 90.00000000
_cell_angle_beta 90.00000000
_cell_angle_gamma 120.00000071
_symmetry_Int_Tables_number 1
_chemical_formula_structural ErCuSi
_chemical_formula_sum 'Er2 Cu2 Si2'
_cell_volume 107.26827522
_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
Er Er0 1 0.00000000 0.00000000 0.50000000 1.0
Er Er1 1 0.00000000 0.00000000 0.00000000 1.0
Cu Cu2 1 0.33333300 0.66666700 0.25000000 1.0
Cu Cu3 1 0.66666700 0.33333300 0.75000000 1.0
Si Si4 1 0.66666700 0.33333300 0.25000000 1.0
Si Si5 1 0.33333300 0.66666700 0.75000000 1.0
