Basic Information
Formula
AlCo2Si
MP-ID
mp-1015811
Elements
3
Sites
4
Density
5.2017
g/cm³
Volume
55.21
ų
Cell a
5.5347
Å
Cell b
5.5347
Å
Cell c
5.5347
Å
α Angle
153.30
°
β Angle
133.23
°
γ Angle
54.66
°
Space Group
Immm
Point Group
mmm
Crystal System
Orthorhombic
Bravais Lattice
oI
Stability
No
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 |
|---|---|---|---|
| 18.04 | 4.9168 | 51.4 | (1,1,-1) |
| 22.16 | 4.0111 | 4.3 | (1,0,0) |
| 34.13 | 2.6272 | 8.5 | (2,1,-1) |
| 36.32 | 2.4736 | 1.1 | (0,1,0) |
| 36.55 | 2.4584 | 59.7 | (2,2,-2) |
| 40.85 | 2.2091 | 100.0 | (0,0,1) |
| 41.09 | 2.1966 | 49.1 | (1,-1,1) |
| 44.98 | 2.0155 | 3.8 | (1,2,-1) |
| 44.99 | 2.0151 | 19.8 | (1,1,0) |
| 45.21 | 2.0056 | 9.8 | (2,0,0) |
| 50.87 | 1.7951 | 7.4 | (3,2,-2) |
| 55.96 | 1.6432 | 64.7 | (2,2,-1) |
| 56.15 | 1.6380 | 32.0 | (3,1,-1) |
| 59.29 | 1.5587 | 4.5 | (2,3,-2) |
| 62.55 | 1.4851 | 2.6 | (2,1,0) |
| 70.36 | 1.3381 | 4.2 | (4,3,-3) |
| 71.70 | 1.3163 | 1.4 | (3,3,-2) |
| 74.21 | 1.2779 | 7.7 | (1,-1,-1) |
| 74.67 | 1.2712 | 4.3 | (3,2,-1) |
| 74.71 | 1.2706 | 15.1 | (1,-1,2) |
| 77.12 | 1.2368 | 1.6 | (0,2,0) |
| 77.54 | 1.2311 | 3.1 | (3,4,-3) |
| 77.61 | 1.2302 | 3.0 | (2,0,1) |
| 77.68 | 1.2292 | 3.6 | (4,4,-4) |
Energy Properties
Formation Energy/atom
0.53876
eV/atom
Energy/atom
-9.95483
eV/atom
Energy above Hull
1.0635
eV/atom
Uncorrected Energy
-5.3971
eV/atom
Volume/atom
13.80
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
2.6727
μB
Mag. Ordering
FM
Mag. Sites
2
Magnetization/Volume
0.048410
μB/ų
Elastic Properties
Elastic data not available
Feature Analysis
Element Composition (atomic fraction)
Composition Info
Major / Matrix Element
Co · 0.500
Element Family
3d-TM
Solute Fraction
0.500
Interstitial Fraction
0.250
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
0.4588
Ω > 1.1 favors solid solution
Atomic Size Mismatch δr
7.472%
δr < 6.6% favors single-phase solid solution
Electronegativity Diff Δχ
0.1201
smaller = more stable mixing
VEC
6.250
valence electron concentration, affects phase stability
Mix Enthalpy ΔH_mix
-29.000
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-1015811
Reference Citation
The crystal structure and related material properties of AlCo2Si were obtained from the Materials Project database (MP-ID: mp-1015811, 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_AlCo2Si
_symmetry_space_group_name_H-M 'P 1'
_cell_length_a 5.53469959
_cell_length_b 5.53469959
_cell_length_c 5.53469959
_cell_angle_alpha 153.30155536
_cell_angle_beta 133.23391099
_cell_angle_gamma 54.66458204
_symmetry_Int_Tables_number 1
_chemical_formula_structural AlCo2Si
_chemical_formula_sum 'Al1 Co2 Si1'
_cell_volume 55.20553844
_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
Al Al0 1 0.00000000 0.00000000 0.00000000 1.0
Co Co1 1 0.26831700 0.26831700 0.00000000 1.0
Co Co2 1 0.73168300 0.73168300 0.00000000 1.0
Si Si3 1 0.50000000 0.50000000 0.00000000 1.0
