CaNi2P2O9

High-Entropy Materials HEA

MP-ID: mp-1043475 · Space group: Pnma (#62)

Materials Project API

Basic Information

Formula

CaNi2P2O9

MP-ID

mp-1043475

Elements

Sites

Density

3.5765

g/cm³

Volume

674.91

Å³

Cell a

6.4663

Cell b

7.3195

Cell c

14.2598

α Angle

90.00

β Angle

90.00

γ Angle

90.00

Space Group

Pnma

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
12.41	7.1299	10.1	(0,0,2)
13.60	6.5117	24.5	(0,1,1)
17.36	5.1073	38.9	(0,1,2)
18.31	4.8461	6.4	(1,1,0)
18.52	4.7898	5.6	(1,0,2)
19.35	4.5883	7.3	(1,1,1)
22.18	4.0079	5.4	(1,1,2)
22.30	3.9865	11.8	(0,1,3)
24.32	3.6597	7.2	(0,2,0)
24.98	3.5650	2.6	(0,0,4)
25.12	3.5449	100.0	(0,2,1)
27.39	3.2559	13.0	(0,2,2)
27.59	3.2331	32.6	(2,0,0)
27.84	3.2050	22.4	(0,1,4)
30.36	2.9445	19.2	(2,0,2)
30.84	2.8998	9.3	(0,2,3)
30.88	2.8958	48.8	(2,1,1)
31.15	2.8716	19.9	(1,1,4)
32.78	2.7318	12.2	(2,1,2)
33.73	2.6574	31.1	(0,1,5)
33.88	2.6459	1.5	(1,2,3)
35.14	2.5537	14.2	(0,2,4)
35.76	2.5111	18.0	(2,1,3)
36.56	2.4579	11.5	(1,1,5)

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Energy Properties

Formation Energy/atom

-2.26084

eV/atom

Energy/atom

-7.18430

eV/atom

Energy above Hull

0.0755

eV/atom

Uncorrected Energy

-6.3797

eV/atom

Volume/atom

12.05

Å³

c/a Ratio

2.2053

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

8.0002

μB

Mag. Ordering

FiM

Mag. Sites

Magnetization/Volume

0.011850

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

O · 0.643

Element Family

Metalloid-Nonmetal

Solute Fraction

0.357

Interstitial Fraction

0.143

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

1.0285

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

8.5511

J/mol·K

Ω Parameter

0.4729

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

46.520%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.8102

smaller = more stable mixing

VEC

4.857

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-7.361

kJ/mol; negative = exothermic mixing

Entropy Norm

0.7419

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (1)

aaaedhme

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-1043475

Reference Citation

The crystal structure and related material properties of CaNi2P2O9 were obtained from the Materials Project database (MP-ID: mp-1043475, 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_CaNi2P2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.46627600
_cell_length_b   7.31946800
_cell_length_c   14.25984200
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   90.00000000
_symmetry_Int_Tables_number   1
_chemical_formula_structural   CaNi2P2O9
_chemical_formula_sum   'Ca4 Ni8 P8 O36'
_cell_volume   674.91404763
_cell_formula_units_Z   4
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  0.75000000  0.37930600  0.27985600  1.0
  Ca  Ca1  1  0.75000000  0.12069400  0.77985600  1.0
  Ca  Ca2  1  0.25000000  0.62069400  0.72014400  1.0
  Ca  Ca3  1  0.25000000  0.87930600  0.22014400  1.0
  Ni  Ni4  1  0.75000000  0.85008200  0.37665500  1.0
  Ni  Ni5  1  0.25000000  0.14991800  0.62334500  1.0
  Ni  Ni6  1  0.25000000  0.35008200  0.12334500  1.0
  Ni  Ni7  1  0.75000000  0.64991800  0.87665500  1.0
  Ni  Ni8  1  0.50000000  0.50000000  0.50000000  1.0
  Ni  Ni9  1  0.50000000  0.00000000  0.00000000  1.0
  Ni  Ni10  1  0.00000000  0.00000000  0.00000000  1.0
  Ni  Ni11  1  0.00000000  0.50000000  0.50000000  1.0
  P  P12  1  0.25000000  0.85875600  0.43543800  1.0
  P  P13  1  0.75000000  0.14124400  0.56456200  1.0
  P  P14  1  0.75000000  0.35875600  0.06456200  1.0
  P  P15  1  0.25000000  0.64124400  0.93543800  1.0
  P  P16  1  0.75000000  0.88667500  0.19240600  1.0
  P  P17  1  0.25000000  0.11332500  0.80759400  1.0
  P  P18  1  0.25000000  0.38667500  0.30759400  1.0
  P  P19  1  0.75000000  0.61332500  0.69240600  1.0
  O  O20  1  0.05233300  0.10523500  0.86780900  1.0
  O  O21  1  0.55233300  0.89476500  0.13219100  1.0
  O  O22  1  0.94766700  0.60523500  0.63219100  1.0
  O  O23  1  0.44766700  0.39476500  0.36780900  1.0
  O  O24  1  0.94766700  0.89476500  0.13219100  1.0
  O  O25  1  0.44766700  0.10523500  0.86780900  1.0
  O  O26  1  0.05233300  0.39476500  0.36780900  1.0
  O  O27  1  0.55233300  0.60523500  0.63219100  1.0
  O  O28  1  0.25000000  0.83274900  0.98735900  1.0
  O  O29  1  0.75000000  0.16725100  0.01264100  1.0
  O  O30  1  0.75000000  0.33274900  0.51264100  1.0
  O  O31  1  0.25000000  0.66725100  0.48735900  1.0
  O  O32  1  0.75000000  0.63058900  0.44651300  1.0
  O  O33  1  0.25000000  0.36941100  0.55348700  1.0
  O  O34  1  0.25000000  0.13058900  0.05348700  1.0
  O  O35  1  0.75000000  0.86941100  0.94651300  1.0
  O  O36  1  0.75000000  0.70918900  0.25331500  1.0
  O  O37  1  0.25000000  0.29081100  0.74668500  1.0
  O  O38  1  0.25000000  0.20918900  0.24668500  1.0
  O  O39  1  0.75000000  0.79081100  0.75331500  1.0
  O  O40  1  0.43656800  0.63773300  0.86726200  1.0
  O  O41  1  0.93656800  0.36226700  0.13273800  1.0
  O  O42  1  0.56343200  0.13773300  0.63273800  1.0
  O  O43  1  0.06343200  0.86226700  0.36726200  1.0
  O  O44  1  0.56343200  0.36226700  0.13273800  1.0
  O  O45  1  0.06343200  0.63773300  0.86726200  1.0
  O  O46  1  0.43656800  0.86226700  0.36726200  1.0
  O  O47  1  0.93656800  0.13773300  0.63273800  1.0
  O  O48  1  0.75000000  0.46251800  0.77054400  1.0
  O  O49  1  0.25000000  0.53748200  0.22945600  1.0
  O  O50  1  0.25000000  0.96251800  0.72945600  1.0
  O  O51  1  0.75000000  0.03748200  0.27054400  1.0
  O  O52  1  0.75000000  0.50639300  0.99138100  1.0
  O  O53  1  0.25000000  0.49360700  0.00861900  1.0
  O  O54  1  0.25000000  0.00639300  0.50861900  1.0
  O  O55  1  0.75000000  0.99360700  0.49138100  1.0

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