Ca(CuO2)2

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-1044717 · Space group: R3m (#160)

Materials Project API

Basic Information

Formula

Ca(CuO2)2

MP-ID

mp-1044717

Elements

Sites

Density

4.4555

g/cm³

Volume

172.31

Å³

Cell a

6.3307

Cell b

6.3307

Cell c

6.3307

α Angle

58.27

β Angle

58.27

γ Angle

58.27

Space Group

R3m

Point Group

Crystal System

Trigonal

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
16.94	5.2355	65.2	(1,1,1)
17.55	5.0548	9.9	(1,0,0)
20.11	4.4152	8.4	(1,1,0)
28.21	3.1632	43.6	(2,1,1)
28.97	3.0824	18.3	(1,0,-1)
33.09	2.7074	46.1	(2,2,1)
33.74	2.6562	100.0	(2,1,0)
34.07	2.6317	82.4	(1,1,-1)
34.26	2.6177	4.6	(2,2,2)
35.52	2.5274	30.5	(2,0,0)
40.88	2.2076	53.1	(2,2,0)
43.76	2.0685	12.9	(3,2,2)
45.31	2.0014	1.5	(2,0,-1)
45.46	1.9953	13.8	(3,2,1)
49.46	1.8427	3.0	(3,3,2)
50.88	1.7948	10.4	(3,1,0)
51.34	1.7796	2.6	(2,-1,-1)
52.43	1.7452	5.6	(3,3,3)
53.34	1.7176	20.9	(3,3,1)
54.01	1.6978	31.2	(3,2,0)
54.46	1.6849	24.7	(2,2,-1)
58.34	1.5816	38.5	(4,2,2)
60.03	1.5412	52.1	(2,0,-2)
61.84	1.5004	3.3	(4,2,1)

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Energy Properties

Formation Energy/atom

-1.45774

eV/atom

Energy/atom

-5.74287

eV/atom

Energy above Hull

0.2525

eV/atom

Uncorrected Energy

-5.3503

eV/atom

Volume/atom

12.31

Å³

c/a Ratio

1.0000

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

1.9986

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.011600

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

0.9557

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

7.9457

J/mol·K

Ω Parameter

2.0114

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

50.317%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.9520

smaller = more stable mixing

VEC

5.714

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-2.286

kJ/mol; negative = exothermic mixing

Entropy Norm

0.8699

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.394

Family

O-rich Multi-Component

Matrix Element

O · 0.571

Related Tasks

Related computation task IDs (3)

aaachlma aaadueat aaaeahfp

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-1044717

Reference Citation

The crystal structure and related material properties of Ca(CuO2)2 were obtained from the Materials Project database (MP-ID: mp-1044717, 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_Ca(CuO2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.33071859
_cell_length_b   6.33071859
_cell_length_c   6.33071850
_cell_angle_alpha   58.27243049
_cell_angle_beta   58.27243049
_cell_angle_gamma   58.27242615
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ca(CuO2)2
_chemical_formula_sum   'Ca2 Cu4 O8'
_cell_volume   172.30975627
_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
  Ca  Ca0  1  0.02074300  0.02074300  0.02074300  1.0
  Ca  Ca1  1  0.62341000  0.62341000  0.62341000  1.0
  Cu  Cu2  1  0.23754400  0.23754400  0.23754400  1.0
  Cu  Cu3  1  0.63086400  0.12080600  0.63086400  1.0
  Cu  Cu4  1  0.63086400  0.63086400  0.12080600  1.0
  Cu  Cu5  1  0.12080600  0.63086400  0.63086400  1.0
  O  O6  1  0.82467900  0.36348800  0.36348800  1.0
  O  O7  1  0.36348800  0.36348800  0.82467900  1.0
  O  O8  1  0.36348800  0.82467900  0.36348800  1.0
  O  O9  1  0.35626100  0.35626100  0.35626100  1.0
  O  O10  1  0.87787500  0.87787500  0.87787500  1.0
  O  O11  1  0.87425500  0.45145900  0.87425500  1.0
  O  O12  1  0.87425500  0.87425500  0.45145900  1.0
  O  O13  1  0.45145900  0.87425500  0.87425500  1.0

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