Ca(Ni2O3)2

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-1043722 · Space group: Cmcm (#63)

Materials Project API

Basic Information

Formula

Ca(Ni2O3)2

MP-ID

mp-1043722

Elements

Sites

Density

5.5079

g/cm³

Volume

223.61

Å³

Cell a

5.1290

Cell b

5.1290

Cell c

15.0906

α Angle

90.00

β Angle

90.00

γ Angle

145.72

Space Group

Cmcm

Point Group

mmm

Crystal System

Orthorhombic

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
11.73	7.5453	63.2	(0,0,2)
18.10	4.9011	3.1	(1,-1,0)
19.04	4.6615	3.2	(1,-1,1)
23.58	3.7727	1.8	(0,0,4)
29.89	2.9895	21.0	(1,-1,4)
30.95	2.8891	3.4	(1,0,0)
31.53	2.8375	12.6	(1,0,1)
33.21	2.6980	36.3	(1,0,2)
34.91	2.5699	100.0	(1,-1,5)
35.84	2.5053	40.7	(1,0,3)
36.67	2.4506	31.2	(2,-2,0)
37.17	2.4189	6.9	(2,-2,1)
38.63	2.3307	2.3	(2,-2,2)
39.28	2.2937	17.4	(1,0,4)
40.31	2.2377	14.8	(1,-1,6)
40.66	2.2191	2.6	(2,-1,0)
40.97	2.2030	2.9	(2,-2,3)
41.11	2.1955	45.9	(2,-1,1)
42.46	2.1289	77.8	(2,-1,2)
44.63	2.0303	58.3	(2,-1,3)
45.99	1.9733	25.2	(1,-1,7)
47.54	1.9128	3.0	(2,-1,4)
48.25	1.8863	4.9	(0,0,8)
51.09	1.7879	3.5	(2,-1,5)

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Energy Properties

Formation Energy/atom

-1.46696

eV/atom

Energy/atom

-6.45004

eV/atom

Energy above Hull

0.0337

eV/atom

Uncorrected Energy

-5.1513

eV/atom

Volume/atom

10.16

Å³

c/a Ratio

2.9422

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

11.9988

μB

Mag. Ordering

FiM

Mag. Sites

Magnetization/Volume

0.053660

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

O · 0.545

Element Family

Metalloid-Nonmetal

Solute Fraction

0.455

Interstitial Fraction

0.000

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

0.9165

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

7.6195

J/mol·K

Ω Parameter

2.1781

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

45.765%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.8871

smaller = more stable mixing

VEC

6.000

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-2.657

kJ/mol; negative = exothermic mixing

Entropy Norm

0.8342

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.544

Family

O-rich Multi-Component

Matrix Element

O · 0.545

Related Tasks

Related computation task IDs (2)

aaachkbf aaadxpgr

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-1043722

Reference Citation

The crystal structure and related material properties of Ca(Ni2O3)2 were obtained from the Materials Project database (MP-ID: mp-1043722, 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_Ca(Ni2O3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.12896594
_cell_length_b   5.12896594
_cell_length_c   15.09059900
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   145.71691022
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ca(Ni2O3)2
_chemical_formula_sum   'Ca2 Ni8 O12'
_cell_volume   223.61047545
_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  0.34420100  0.65579900  0.75000000  1.0
  Ca  Ca1  1  0.65579900  0.34420100  0.25000000  1.0
  Ni  Ni2  1  0.13676400  0.86323600  0.04181400  1.0
  Ni  Ni3  1  0.59071900  0.40928100  0.63078800  1.0
  Ni  Ni4  1  0.86323600  0.13676400  0.95818600  1.0
  Ni  Ni5  1  0.40928100  0.59071900  0.36921200  1.0
  Ni  Ni6  1  0.13676400  0.86323600  0.45818600  1.0
  Ni  Ni7  1  0.86323600  0.13676400  0.54181400  1.0
  Ni  Ni8  1  0.40928100  0.59071900  0.13078800  1.0
  Ni  Ni9  1  0.59071900  0.40928100  0.86921200  1.0
  O  O10  1  0.50000000  0.50000000  0.50000000  1.0
  O  O11  1  0.50000000  0.50000000  0.00000000  1.0
  O  O12  1  0.95718700  0.04281300  0.84740100  1.0
  O  O13  1  0.04281300  0.95718700  0.15259900  1.0
  O  O14  1  0.04281300  0.95718700  0.34740100  1.0
  O  O15  1  0.95718700  0.04281300  0.65259900  1.0
  O  O16  1  0.22387500  0.77612500  0.92314100  1.0
  O  O17  1  0.77612500  0.22387500  0.07685900  1.0
  O  O18  1  0.77612500  0.22387500  0.42314100  1.0
  O  O19  1  0.22387500  0.77612500  0.57685900  1.0
  O  O20  1  0.66955500  0.33044500  0.75000000  1.0
  O  O21  1  0.33044500  0.66955500  0.25000000  1.0

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