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Ca(Al2Cu)4

High-Entropy Materials HEA Traditional Materials TRA Elasticity Data ELA

MP-ID: mp-10877 · Space group: I4/mmm (#139)

Basic Information

Formula
Ca(Al2Cu)4
MP-ID
mp-10877
Elements
3
Sites
13
Density
4.3241
g/cm³
Volume
195.89
ų
Cell a
5.0988
Å
Cell b
6.7022
Å
Cell c
6.7016
Å
α Angle
81.68
°
β Angle
67.65
°
γ Angle
67.64
°
Space Group
I4/mmm
Point Group
4/mmm
Crystal System
Tetragonal
Bravais Lattice
Tetragonal I
Stability
Yes
Packing Fraction
0.7400

X-ray Diffraction

Diffraction Pattern
X-axis: 2θ (°); Y-axis: relative intensity; CuKa ; λ=1.5406 Å
Diffraction Peaks (Top 24)
2θd (Å)Ihkl
20.26 4.3829 100.0 (0,1,1)
28.72 3.1081 1.4 (1,1,-1)
28.72 3.1079 1.4 (1,2,0)
28.73 3.1077 1.4 (1,-1,1)
28.81 3.0992 19.0 (0,0,2)
28.81 3.0992 19.0 (0,2,0)
32.29 2.7720 1.7 (0,1,2)
35.40 2.5353 9.8 (1,2,-1)
35.41 2.5350 9.8 (1,-1,2)
40.95 2.2039 55.8 (2,2,0)
40.96 2.2036 55.7 (2,0,2)
41.13 2.1947 10.1 (1,1,-2)
41.13 2.1945 10.1 (1,3,0)
41.13 2.1945 10.1 (1,-2,1)
41.14 2.1943 5.1 (1,0,3)
41.14 2.1943 5.1 (1,1,3)
41.19 2.1915 76.8 (0,2,2)
43.82 2.0661 1.4 (0,0,3)
43.82 2.0661 1.4 (0,3,0)
46.10 1.9691 21.0 (2,1,-1)
46.10 1.9689 42.0 (2,-1,1)
46.11 1.9686 21.0 (2,1,3)
46.26 1.9624 1.0 (1,2,-2)
46.26 1.9624 1.0 (1,-1,-2)
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Energy Properties

Formation Energy/atom
-0.29085
eV/atom
Energy/atom
-8.31256
eV/atom
Energy above Hull
0.0000
eV/atom
Uncorrected Energy
-8.3126
eV/atom
Volume/atom
15.07
ų
c/a Ratio
1.3144

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
81.186
GPa
GVRH
60.736
GPa
Young's Modulus E
145.840
GPa
Poisson Ratio ν
0.201
Pugh Ratio K/G
1.337
Vickers Hardness Est.
12.736
GPa
Ductility
Ductile
Anisotropy
0.015
Lame λ
40.695
GPa

Feature Analysis

Composition Overview

Element Composition (atomic fraction)
Composition Info
Major / Matrix Element
Al · 0.615
Element Family
PostTransition-Noble
Solute Fraction
0.385
Interstitial Fraction
0.000

High-Entropy Alloy Features

Composite Radar (normalized)
Element-Class Share
Mix Entropy ΔS/R
0.8587
HEA criterion (>1.0 = high entropy)
Mix Entropy ΔS
7.1396
J/mol·K
Ω Parameter
1.3113
Ω > 1.1 favors solid solution
Atomic Size Mismatch δr
12.016%
δr < 6.6% favors single-phase solid solution
Electronegativity Diff Δχ
0.2296
smaller = more stable mixing
VEC
5.385
valence electron concentration, affects phase stability
Mix Enthalpy ΔH_mix
-5.870
kJ/mol; negative = exothermic mixing
Entropy Norm
0.7817
SS Former
0
Phase Tendency
IM

Traditional Material Features

ROM Blended-Feature Radar
Rating & Classification
Tier
A
Score
0.775
Family
Al-based Alloy
Matrix Element
Al · 0.615

Elasticity Features

Elastic Modulus Comparison (GPa)
Elastic Features
Elastic Anisotropy AU
0.0150
Homogeneous Poisson ν
0.2010
Debye Temperature
498.6
K
Sound Velocity
4,137.8
m/s
Homogeneity
0.2010

Related Tasks

Citation & References

Materials Project Page
https://materialsproject.org/materials/mp-10877
Reference Citation

The crystal structure and related material properties of Ca(Al2Cu)4 were obtained from the Materials Project database (MP-ID: mp-10877, 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

BibTeX
@article{Horton2025,
  author  = {Horton, Matthew K. and Huck, Patrick and Yang, Ruo Xi and Munro, Jason M. and Dwaraknath, Shyam and Ganose, Alex M. and Kingsbury, Ryan S. and Wen, Mingjian and Shen, Jimmy X. and Mathis, Tyler S. and Kaplan, Aaron D. and Berket, Karlo and Riebesell, Janosh and George, Janine and Rosen, Andrew S. and Spotte-Smith, Evan W. C. and McDermott, Matthew J. and Cohen, Orion A. and Dunn, Alex and Kuner, Matthew C. and Rignanese, Gian-Marco and Petretto, Guido and Waroquiers, David and Griffin, Sinead M. and Neaton, Jeffrey B. and Chrzan, Daryl C. and Asta, Mark and Hautier, Geoffroy and Cholia, Shreyas and Ceder, Gerbrand and Ong, Shyue Ping and Jain, Anubhav and Persson, Kristin A.},
  title   = {Accelerated data-driven materials science with the Materials Project},
  journal = {Nature Materials},
  year    = {2025},
  volume  = {24},
  number  = {10},
  pages   = {1522--1532},
  month   = {oct},
  doi     = {10.1038/s41563-025-02272-0},
  issn    = {1476-4660},
  url     = {https://doi.org/10.1038/s41563-025-02272-0},
  abstract = {The Materials Project was launched formally in 2011 to drive materials discovery forwards through high-throughput computation and open data. More than a decade later, the Materials Project has become an indispensable tool used by more than 600,000 materials researchers around the world. This Perspective describes how the Materials Project, as a data platform and a software ecosystem, has helped to shape research in data-driven materials science. We cover how sustainable software and computational methods have accelerated materials design while becoming more open source and collaborative in nature. Next, we present cases where the Materials Project was used to understand and discover functional materials. We then describe our efforts to meet the needs of an expanding user base, through technical infrastructure updates ranging from data architecture and cloud resources to interactive web applications. Finally, we discuss opportunities to better aid the research community, with the vision that more accessible and easy-to-understand materials data will result in democratized materials knowledge and an increasingly collaborative community.}
}

3D Crystal Structure Rendering

Loading 3D structure…

Style: Ball & Stick
Raw CIF Data
# generated using pymatgen
data_Ca(Al2Cu)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.09881202
_cell_length_b   6.70215866
_cell_length_c   6.70163892
_cell_angle_alpha   81.68451031
_cell_angle_beta   67.65374886
_cell_angle_gamma   67.64241947
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ca(Al2Cu)4
_chemical_formula_sum   'Ca1 Al8 Cu4'
_cell_volume   195.89434361
_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
  Ca  Ca0  1  -0.00000000  0.00000000  0.00000000  1.0
  Al  Al1  1  0.34846646  0.65160640  0.65159786  1.0
  Al  Al2  1  0.00007287  0.34839360  0.65159786  1.0
  Al  Al3  1  0.99992713  0.65160640  0.34840214  1.0
  Al  Al4  1  0.65153354  0.34839360  0.34840214  1.0
  Al  Al5  1  0.27900930  0.22105241  0.22104715  1.0
  Al  Al6  1  0.50006171  0.77894759  0.22104715  1.0
  Al  Al7  1  0.49993829  0.22105241  0.77895285  1.0
  Al  Al8  1  0.72099070  0.77894759  0.77895285  1.0
  Cu  Cu9  1  0.50000000  0.00000000  0.50000000  1.0
  Cu  Cu10  1  -0.00000000  0.50000000  0.00000000  1.0
  Cu  Cu11  1  0.50000000  0.50000000  0.00000000  1.0
  Cu  Cu12  1  -0.00000000  0.00000000  0.50000000  1.0
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