Fe2Ni(PO4)3

High-Entropy Materials HEA

MP-ID: mp-774420 · Space group: R-3c (#167)

Materials Project API

Basic Information

Formula

Fe2Ni(PO4)3

MP-ID

mp-774420

Elements

Sites

Density

3.4084

g/cm³

Volume

443.64

Å³

Cell a

8.4923

Cell b

8.4923

Cell c

8.4923

α Angle

61.08

β Angle

61.08

γ Angle

61.08

Space Group

R-3c

Point Group

-3m

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
14.64	6.0526	1.5	(1,1,0)
14.64	6.0526	3.0	(1,0,1)
20.58	4.3155	81.9	(1,0,-1)
20.58	4.3155	40.9	(1,-1,0)
20.93	4.2450	11.1	(2,1,1)
24.35	3.6553	86.6	(2,1,0)
24.35	3.6553	43.3	(2,0,1)
25.35	3.5138	7.8	(0,0,2)
25.35	3.5138	15.5	(2,0,0)
29.52	3.0263	3.0	(2,2,0)
29.52	3.0263	5.9	(2,0,2)
31.97	2.7991	19.4	(2,0,-1)
32.87	2.7248	5.3	(2,1,-1)
32.87	2.7248	2.6	(2,-1,1)
33.32	2.6891	100.0	(3,2,1)
36.05	2.4916	18.9	(1,1,-2)
36.05	2.4916	37.9	(2,-1,-1)
36.26	2.4778	4.0	(3,1,0)
36.87	2.4377	2.0	(3,3,2)
38.62	2.3311	2.3	(3,2,0)
41.87	2.1578	2.9	(2,0,-2)
42.60	2.1225	13.9	(4,2,2)
43.98	2.0588	2.0	(3,1,-1)
44.42	2.0394	1.1	(4,1,2)

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Energy Properties

Formation Energy/atom

-2.19887

eV/atom

Energy/atom

-7.66232

eV/atom

Energy above Hull

0.0498

eV/atom

Uncorrected Energy

-6.8125

eV/atom

Volume/atom

12.32

Å³

c/a Ratio

1.0000

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

25.2812

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.056990

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

O · 0.667

Element Family

Metalloid-Nonmetal

Solute Fraction

0.333

Interstitial Fraction

0.167

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

0.9736

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

8.0949

J/mol·K

Ω Parameter

0.7729

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

34.769%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.6749

smaller = more stable mixing

VEC

4.944

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-4.049

kJ/mol; negative = exothermic mixing

Entropy Norm

0.7023

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (2)

aaabzixk aaadwqxp

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-774420

Reference Citation

The crystal structure and related material properties of Fe2Ni(PO4)3 were obtained from the Materials Project database (MP-ID: mp-774420, 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_Fe2Ni(PO4)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.49224612
_cell_length_b   8.49224612
_cell_length_c   8.49224594
_cell_angle_alpha   61.08463059
_cell_angle_beta   61.08463059
_cell_angle_gamma   61.08462206
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Fe2Ni(PO4)3
_chemical_formula_sum   'Fe4 Ni2 P6 O24'
_cell_volume   443.63879499
_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
  Fe  Fe0  1  0.14423600  0.14423600  0.14423600  1.0
  Fe  Fe1  1  0.35576400  0.35576400  0.35576400  1.0
  Fe  Fe2  1  0.64423600  0.64423600  0.64423600  1.0
  Fe  Fe3  1  0.85576400  0.85576400  0.85576400  1.0
  Ni  Ni4  1  0.00000000  0.00000000  0.00000000  1.0
  Ni  Ni5  1  0.50000000  0.50000000  0.50000000  1.0
  P  P6  1  0.75000000  0.04634700  0.45365300  1.0
  P  P7  1  0.04634700  0.45365300  0.75000000  1.0
  P  P8  1  0.45365300  0.75000000  0.04634700  1.0
  P  P9  1  0.54634700  0.25000000  0.95365300  1.0
  P  P10  1  0.95365300  0.54634700  0.25000000  1.0
  P  P11  1  0.25000000  0.95365300  0.54634700  1.0
  O  O12  1  0.31975600  0.10918300  0.50483800  1.0
  O  O13  1  0.50483800  0.31975600  0.10918300  1.0
  O  O14  1  0.90759100  0.06100900  0.25397800  1.0
  O  O15  1  0.10918300  0.50483800  0.31975600  1.0
  O  O16  1  0.81975600  0.00483800  0.60918300  1.0
  O  O17  1  0.59240900  0.24602200  0.43899100  1.0
  O  O18  1  0.06100900  0.25397800  0.90759100  1.0
  O  O19  1  0.24602200  0.43899100  0.59240900  1.0
  O  O20  1  0.39081700  0.18024400  0.99516200  1.0
  O  O21  1  0.43899100  0.59240900  0.24602200  1.0
  O  O22  1  0.74602200  0.09240900  0.93899100  1.0
  O  O23  1  0.99516200  0.39081700  0.18024400  1.0
  O  O24  1  0.00483800  0.60918300  0.81975600  1.0
  O  O25  1  0.25397800  0.90759100  0.06100900  1.0
  O  O26  1  0.56100900  0.40759100  0.75397800  1.0
  O  O27  1  0.60918300  0.81975600  0.00483800  1.0
  O  O28  1  0.75397800  0.56100900  0.40759100  1.0
  O  O29  1  0.93899100  0.74602200  0.09240900  1.0
  O  O30  1  0.40759100  0.75397800  0.56100900  1.0
  O  O31  1  0.18024400  0.99516200  0.39081700  1.0
  O  O32  1  0.89081700  0.49516200  0.68024400  1.0
  O  O33  1  0.09240900  0.93899100  0.74602200  1.0
  O  O34  1  0.49516200  0.68024400  0.89081700  1.0
  O  O35  1  0.68024400  0.89081700  0.49516200  1.0

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