BaCa(CuO2)4

High-Entropy Materials HEA

MP-ID: mp-1046980 · Space group: P-31m (#162)

Materials Project API

Basic Information

Formula

BaCa(CuO2)4

MP-ID

mp-1046980

Elements

Sites

Density

4.7734

g/cm³

Volume

194.67

Å³

Cell a

5.3829

Cell b

5.3829

Cell c

7.7578

α Angle

90.00

β Angle

90.00

γ Angle

120.00

Space Group

P-31m

Point Group

-3m

Crystal System

Trigonal

Bravais Lattice

Stability

Packing Fraction

0.7405

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
11.41	7.7578	21.6	(0,0,0,1)
22.25	3.9958	8.7	(1,0,-1,1)
22.93	3.8789	9.0	(0,0,0,2)
29.97	2.9817	100.0	(1,0,-1,2)
33.29	2.6914	82.8	(2,-1,-1,0)
34.69	2.5859	2.8	(0,0,0,3)
35.30	2.5427	23.3	(2,-1,-1,1)
39.87	2.2613	5.5	(1,0,-1,3)
40.41	2.2323	2.2	(2,0,-2,1)
40.81	2.2113	1.6	(2,-1,-1,2)
45.40	1.9979	31.6	(2,0,-2,2)
46.84	1.9394	13.7	(0,0,0,4)
52.88	1.7313	2.4	(2,0,-2,3)
53.32	1.7182	2.1	(3,-1,-2,1)
57.44	1.6042	20.3	(3,-1,-2,2)
57.44	1.6042	10.2	(2,1,-3,2)
58.67	1.5735	33.8	(2,-1,-1,4)
59.49	1.5539	8.0	(3,-3,0,0)
59.49	1.5539	16.0	(3,0,-3,0)
60.79	1.5236	1.3	(3,0,-3,1)
63.94	1.4561	2.9	(3,-1,-2,3)
64.61	1.4425	1.4	(3,0,-3,2)
69.90	1.3457	5.9	(4,-2,-2,0)
69.90	1.3457	2.9	(2,2,-4,0)

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Energy Properties

Formation Energy/atom

-1.43110

eV/atom

Energy/atom

-5.71003

eV/atom

Energy above Hull

0.2024

eV/atom

Uncorrected Energy

-5.3175

eV/atom

Volume/atom

13.90

Å³

c/a Ratio

1.4412

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Total Mag. Moment

0.0044

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.000020

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

4.3765

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

52.338%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.9659

smaller = more stable mixing

VEC

5.714

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 (3)

aaachouz aaadazit aaaduvnv

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-1046980

Reference Citation

The crystal structure and related material properties of BaCa(CuO2)4 were obtained from the Materials Project database (MP-ID: mp-1046980, 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_BaCa(CuO2)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.38284654
_cell_length_b   5.38284654
_cell_length_c   7.75776700
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   120.00000659
_symmetry_Int_Tables_number   1
_chemical_formula_structural   BaCa(CuO2)4
_chemical_formula_sum   'Ba1 Ca1 Cu4 O8'
_cell_volume   194.66654961
_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
  Ba  Ba0  1  0.00000000  0.00000000  0.00000000  1.0
  Ca  Ca1  1  0.00000000  0.00000000  0.50000000  1.0
  Cu  Cu2  1  0.33333300  0.66666700  0.76065800  1.0
  Cu  Cu3  1  0.66666700  0.33333300  0.76065800  1.0
  Cu  Cu4  1  0.33333300  0.66666700  0.23934200  1.0
  Cu  Cu5  1  0.66666700  0.33333300  0.23934200  1.0
  O  O6  1  0.33086900  0.33086900  0.70144800  1.0
  O  O7  1  0.66913100  0.00000000  0.70144800  1.0
  O  O8  1  0.00000000  0.66913100  0.70144800  1.0
  O  O9  1  0.66913100  0.66913100  0.29855200  1.0
  O  O10  1  0.00000000  0.33086900  0.29855200  1.0
  O  O11  1  0.33086900  0.00000000  0.29855200  1.0
  O  O12  1  0.33333300  0.66666700  0.00000000  1.0
  O  O13  1  0.66666700  0.33333300  0.00000000  1.0

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