Ca4MgAl3

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-640340 · Space group: Pbcm (#57)

Materials Project API

Basic Information

Formula

Ca4MgAl3

MP-ID

mp-640340

Elements

Sites

Density

2.0111

g/cm³

Volume

877.08

Å³

Cell a

5.8565

Cell b

6.1750

Cell c

24.2530

α Angle

90.00

β Angle

90.00

γ Angle

90.00

Space Group

Pbcm

Point Group

mmm

Crystal System

Orthorhombic

Bravais Lattice

Stability

Yes

Packing Fraction

X-ray Diffraction

Diffraction Pattern

Target / Radiation

X-axis: 2θ (°); Y-axis: relative intensity; Cu Kα ; λ=1.5418 Å

Diffraction Peaks (Top 24)

2θ	d (Å)	I	hkl
7.29	12.1265	10.1	(0,0,2)
20.53	4.3263	2.8	(0,1,4)
23.32	3.8145	4.6	(0,1,5)
23.65	3.7614	2.0	(1,1,3)
25.60	3.4798	24.9	(1,1,4)
26.35	3.3820	2.9	(0,1,6)
27.91	3.1963	39.3	(1,1,5)
29.46	3.0316	1.8	(0,0,8)
29.56	3.0216	7.2	(0,1,7)
29.86	2.9921	20.6	(0,2,2)
30.52	2.9287	28.2	(1,1,6)
30.53	2.9282	54.1	(2,0,0)
31.01	2.8843	10.2	(0,2,3)
32.54	2.7513	4.9	(0,2,4)
32.91	2.7214	43.8	(0,1,8)
33.00	2.7140	12.6	(1,2,1)
33.28	2.6923	52.4	(1,0,8)
33.37	2.6853	74.2	(1,1,7)
33.64	2.6645	100.0	(1,2,2)
33.88	2.6458	19.0	(2,1,0)
34.00	2.6368	32.6	(2,0,4)
34.09	2.6302	12.0	(2,1,1)
34.43	2.6046	16.9	(0,2,5)
34.67	2.5875	31.2	(1,2,3)

Get direct link

Energy Properties

Formation Energy/atom

-0.21142

eV/atom

Energy/atom

-2.82262

eV/atom

Energy above Hull

0.0000

eV/atom

Uncorrected Energy

-6.8024

eV/atom

Volume/atom

27.41

Å³

c/a Ratio

4.1413

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Total Mag. Moment

0.4327

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.000490

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

Ca · 0.500

Element Family

Alkali-AlkEarth

Solute Fraction

0.500

Interstitial Fraction

0.000

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

0.9743

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

8.1005

J/mol·K

Ω Parameter

0.5303

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

14.765%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.2828

smaller = more stable mixing

VEC

2.375

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-15.625

kJ/mol; negative = exothermic mixing

Entropy Norm

0.8869

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.530

Family

Ca-rich Multi-Component

Matrix Element

Ca · 0.500

Related Tasks

Related computation task IDs (2)

aaacbawx aaagadbt

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-640340

Reference Citation

The crystal structure and related material properties of Ca4MgAl3 were obtained from the Materials Project database (MP-ID: mp-640340, 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

Loading 3D structure…

Style: Ball & Stick | Drag to rotate · Scroll to zoom · Right-click to pan

Raw CIF Data

# generated using pymatgen
data_Ca4MgAl3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.85645151
_cell_length_b   6.17501313
_cell_length_c   24.25304459
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   90.00000000
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ca4MgAl3
_chemical_formula_sum   'Ca16 Mg4 Al12'
_cell_volume   877.07897904
_cell_formula_units_Z   4
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  0.75000000  0.68608961  0.28985018  1.0
  Ca  Ca1  1  0.25000000  0.31391039  0.71014982  1.0
  Ca  Ca2  1  0.25000000  0.24349374  0.12374107  1.0
  Ca  Ca3  1  0.25000000  0.91976600  0.35741935  1.0
  Ca  Ca4  1  0.75000000  0.24349374  0.37625893  1.0
  Ca  Ca5  1  0.25000000  0.08023400  0.85741935  1.0
  Ca  Ca6  1  0.25000000  0.50341779  0.95381296  1.0
  Ca  Ca7  1  0.75000000  0.50341779  0.54618704  1.0
  Ca  Ca8  1  0.75000000  0.08023400  0.64258065  1.0
  Ca  Ca9  1  0.75000000  0.49658221  0.04618704  1.0
  Ca  Ca10  1  0.25000000  0.68608961  0.21014982  1.0
  Ca  Ca11  1  0.25000000  0.49658221  0.45381296  1.0
  Ca  Ca12  1  0.25000000  0.75650626  0.62374107  1.0
  Ca  Ca13  1  0.75000000  0.31391039  0.78985018  1.0
  Ca  Ca14  1  0.75000000  0.91976600  0.14258065  1.0
  Ca  Ca15  1  0.75000000  0.75650626  0.87625893  1.0
  Mg  Mg16  1  -0.00000000  0.00000000  -0.00000000  1.0
  Mg  Mg17  1  0.50000000  0.00000000  -0.00000000  1.0
  Mg  Mg18  1  0.50000000  0.00000000  0.50000000  1.0
  Mg  Mg19  1  -0.00000000  0.00000000  0.50000000  1.0
  Al  Al20  1  0.00000000  0.83093714  0.75000000  1.0
  Al  Al21  1  0.75000000  0.25419303  0.92455454  1.0
  Al  Al22  1  0.25000000  0.74580697  0.07544546  1.0
  Al  Al23  1  0.75000000  0.74580697  0.42455454  1.0
  Al  Al24  1  -0.00000000  0.16906286  0.25000000  1.0
  Al  Al25  1  0.50000000  0.16906286  0.25000000  1.0
  Al  Al26  1  0.50000000  0.83093714  0.75000000  1.0
  Al  Al27  1  0.25000000  0.58779063  0.82251478  1.0
  Al  Al28  1  0.75000000  0.58779063  0.67748522  1.0
  Al  Al29  1  0.25000000  0.41220937  0.32251478  1.0
  Al  Al30  1  0.75000000  0.41220937  0.17748522  1.0
  Al  Al31  1  0.25000000  0.25419303  0.57544546  1.0

Get direct link