CaEu(CuO2)4

High-Entropy Materials HEA

MP-ID: mp-3296566 · Space group: I-4 (#82)

Materials Project API

Basic Information

Formula

CaEu(CuO2)4

MP-ID

mp-3296566

Elements

Sites

Density

6.0857

g/cm³

Volume

156.68

Å³

Cell a

6.2492

Cell b

6.2492

Cell c

6.2492

α Angle

125.28

β Angle

125.28

γ Angle

81.07

Space Group

I-4

Point Group

-4

Crystal System

Tetragonal

Bravais Lattice

Stability

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
18.05	4.9150	19.8	(1,0,-1)
18.68	4.7495	9.0	(1,1,-1)
21.88	4.0614	13.5	(1,-1,0)
28.93	3.0867	18.9	(2,0,-1)
28.93	3.0867	18.9	(1,1,-2)
31.14	2.8718	3.1	(1,-1,1)
31.14	2.8718	3.1	(1,-1,-1)
32.28	2.7729	51.2	(2,1,-2)
36.23	2.4796	17.8	(1,-2,1)
36.23	2.4796	100.0	(2,-1,-1)
36.57	2.4575	44.8	(2,0,-2)
44.18	2.0500	7.1	(3,1,-2)
45.47	1.9948	4.4	(3,0,-2)
48.51	1.8768	1.9	(2,-1,-2)
48.77	1.8672	1.7	(3,-1,-1)
48.77	1.8672	1.7	(1,1,-3)
49.83	1.8301	5.5	(3,1,-3)
49.83	1.8301	1.8	(1,3,-1)
50.23	1.8163	2.2	(2,-2,1)
50.61	1.8037	23.4	(3,2,-3)
54.06	1.6965	9.3	(3,-1,-2)
54.06	1.6965	9.3	(1,-3,0)
56.14	1.6383	14.3	(3,0,-3)
56.14	1.6383	4.8	(0,3,0)

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Energy Properties

Formation Energy/atom

-1.32952

eV/atom

Energy/atom

-11.09571

eV/atom

Energy above Hull

0.2517

eV/atom

Uncorrected Energy

-11.0957

eV/atom

Volume/atom

11.19

Å³

c/a Ratio

1.0000

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

0.9837

μB

Mag. Ordering

FiM

Mag. Sites

Magnetization/Volume

0.006280

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

O · 0.571

Element Family

Metalloid-Nonmetal

Solute Fraction

0.429

Interstitial Fraction

0.000

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

1.0547

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

8.7689

J/mol·K

Ω Parameter

4.4307

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

49.109%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.9283

smaller = more stable mixing

VEC

6.071

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-1.143

kJ/mol; negative = exothermic mixing

Entropy Norm

0.7608

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (1)

aaahfopa

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-3296566

Reference Citation

The crystal structure and related material properties of CaEu(CuO2)4 were obtained from the Materials Project database (MP-ID: mp-3296566, 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…

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Raw CIF Data

# generated using pymatgen
data_CaEu(CuO2)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.24914759
_cell_length_b   6.24914754
_cell_length_c   6.24914738
_cell_angle_alpha   125.28354239
_cell_angle_beta   125.28353600
_cell_angle_gamma   81.06892967
_symmetry_Int_Tables_number   1
_chemical_formula_structural   CaEu(CuO2)4
_chemical_formula_sum   'Ca1 Eu1 Cu4 O8'
_cell_volume   156.68041463
_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
  Eu  Eu1  1  0.75000000  0.25000000  0.50000000  1.0
  Cu  Cu2  1  0.87605919  0.62524299  0.25188788  1.0
  Cu  Cu3  1  0.37335611  0.62417231  0.74811212  1.0
  Cu  Cu4  1  0.37582769  0.12394081  0.74918380  1.0
  Cu  Cu5  1  0.37475701  0.62664389  0.25081620  1.0
  O  O6  1  0.02458596  0.94211104  0.36683665  1.0
  O  O7  1  0.05788896  0.42472560  0.08247492  1.0
  O  O8  1  0.34225068  0.97541404  0.91752508  1.0
  O  O9  1  0.17397228  0.59281539  0.86643707  1.0
  O  O10  1  0.40718461  0.27362068  0.58115690  1.0
  O  O11  1  0.69246478  0.82602772  0.41884310  1.0
  O  O12  1  0.57527440  0.65774932  0.63316335  1.0
  O  O13  1  0.72637932  0.30753522  0.13356293  1.0

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