Ca(NiO2)2

高熵材料 HEA 传统材料 TRA

MP-ID: mp-1041378 · Space group: P3m1 (#156)

Materials Project API

Basic Information

Formula

Ca(NiO2)2

MP-ID

mp-1041378

Elements

Sites

Density

4.5046

g/cm³

Volume

489.83

Å³

Cell a

6.1417

Cell b

6.1417

Cell c

14.9945

α Angle

90.00

β Angle

90.00

γ Angle

120.00

Space Group

P3m1

Point Group

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
5.89	14.9945	5.8	(0,0,0,1)
11.80	7.4973	2.9	(0,0,0,2)
16.67	5.3189	3.8	(1,0,-1,0)
17.69	5.0129	31.4	(1,0,-1,1)
17.75	4.9982	47.6	(0,0,0,3)
20.47	4.3381	8.6	(1,0,-1,2)
24.44	3.6424	3.3	(1,0,-1,3)
29.08	3.0709	22.8	(2,-1,-1,0)
29.14	3.0641	32.4	(1,0,-1,4)
34.24	2.6186	76.5	(2,0,-2,1)
34.27	2.6165	100.0	(2,-1,-1,3)
34.33	2.6123	55.3	(1,0,-1,5)
35.83	2.5064	9.8	(2,-2,0,2)
35.83	2.5064	19.7	(2,0,-2,2)
35.94	2.4991	5.0	(0,0,0,6)
39.86	2.2619	1.3	(1,0,-1,6)
41.64	2.1690	64.9	(2,0,-2,4)
45.52	1.9925	1.1	(3,-1,-2,1)
45.59	1.9898	4.5	(2,0,-2,5)
45.66	1.9870	6.3	(1,0,-1,7)
46.87	1.9383	6.9	(2,-1,-1,6)
50.09	1.8212	4.7	(2,0,-2,6)
51.55	1.7730	3.1	(3,0,-3,0)
51.59	1.7717	9.5	(3,-1,-2,4)

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Energy Properties

Formation Energy/atom

-1.56659

eV/atom

Energy/atom

-6.33198

eV/atom

Energy above Hull

0.0955

eV/atom

Uncorrected Energy

-5.2134

eV/atom

Volume/atom

11.66

Å³

c/a Ratio

2.4414

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

14.0001

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.028580

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

O · 0.571

Element Family

Metalloid-Nonmetal

Solute Fraction

0.429

Interstitial Fraction

0.000

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

1.6573

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

50.254%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.9497

smaller = more stable mixing

VEC

5.429

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-3.281

kJ/mol; negative = exothermic mixing

Entropy Norm

0.8699

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (2)

aaadrobu aaaefybk

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-1041378

Reference Citation

The crystal structure and related material properties of Ca(NiO2)2 were obtained from the Materials Project database (MP-ID: mp-1041378, 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(NiO2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.14172263
_cell_length_b   6.14172263
_cell_length_c   14.99450900
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   120.00000676
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ca(NiO2)2
_chemical_formula_sum   'Ca6 Ni12 O24'
_cell_volume   489.82759646
_cell_formula_units_Z   6
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  0.33333300  0.66666700  0.04680900  1.0
  Ca  Ca1  1  0.00000000  0.00000000  0.38591800  1.0
  Ca  Ca2  1  0.66666700  0.33333300  0.33584800  1.0
  Ca  Ca3  1  0.66666700  0.33333300  0.74542300  1.0
  Ca  Ca4  1  0.00000000  0.00000000  0.98937900  1.0
  Ca  Ca5  1  0.00000000  0.00000000  0.62567600  1.0
  Ni  Ni6  1  0.32456000  0.16228000  0.16558900  1.0
  Ni  Ni7  1  0.83772000  0.67544000  0.16558900  1.0
  Ni  Ni8  1  0.99608800  0.49804400  0.51072500  1.0
  Ni  Ni9  1  0.83772000  0.16228000  0.16558900  1.0
  Ni  Ni10  1  0.50195600  0.00391200  0.51072500  1.0
  Ni  Ni11  1  0.33333300  0.66666700  0.66161600  1.0
  Ni  Ni12  1  0.33333300  0.66666700  0.27667400  1.0
  Ni  Ni13  1  0.65452500  0.82726300  0.82703400  1.0
  Ni  Ni14  1  0.50195600  0.49804400  0.51072500  1.0
  Ni  Ni15  1  0.17273700  0.34547500  0.82703400  1.0
  Ni  Ni16  1  0.17273700  0.82726300  0.82703400  1.0
  Ni  Ni17  1  0.66666700  0.33333300  0.95315700  1.0
  O  O18  1  0.71158000  0.85579000  0.10122400  1.0
  O  O19  1  0.00000000  0.00000000  0.24163800  1.0
  O  O20  1  0.14421000  0.28842000  0.10122400  1.0
  O  O21  1  0.14421000  0.85579000  0.10122400  1.0
  O  O22  1  0.36997400  0.18498700  0.45061200  1.0
  O  O23  1  0.51129600  0.48870400  0.22956300  1.0
  O  O24  1  0.66666700  0.33333300  0.58891800  1.0
  O  O25  1  0.51129600  0.02259200  0.22956300  1.0
  O  O26  1  0.66666700  0.33333300  0.07616100  1.0
  O  O27  1  0.81501300  0.63002600  0.45061200  1.0
  O  O28  1  0.81501300  0.18498700  0.45061200  1.0
  O  O29  1  0.97740800  0.48870400  0.22956300  1.0
  O  O30  1  0.06675500  0.53337800  0.73829800  1.0
  O  O31  1  0.19798500  0.80201500  0.57735800  1.0
  O  O32  1  0.19798500  0.39597000  0.57735800  1.0
  O  O33  1  0.33333300  0.66666700  0.89329800  1.0
  O  O34  1  0.33333300  0.66666700  0.41778600  1.0
  O  O35  1  0.46662200  0.93324500  0.73829800  1.0
  O  O36  1  0.46662200  0.53337800  0.73829800  1.0
  O  O37  1  0.60403000  0.80201500  0.57735800  1.0
  O  O38  1  0.82468500  0.17531500  0.89591400  1.0
  O  O39  1  0.82468500  0.64936900  0.89591400  1.0
  O  O40  1  0.00000000  0.00000000  0.77264500  1.0
  O  O41  1  0.35063100  0.17531500  0.89591400  1.0

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