Fe3Ni(PO4)4

High-Entropy Materials HEA

MP-ID: mp-775017 · Space group: Pm (#6)

Materials Project API

Basic Information

Formula

Fe3Ni(PO4)4

MP-ID

mp-775017

Elements

Sites

Density

3.5228

g/cm³

Volume

285.70

Å³

Cell a

5.8988

Cell b

4.8704

Cell c

9.9445

α Angle

89.81

β Angle

90.00

γ Angle

90.00

Space Group

Point Group

Crystal System

Monoclinic

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
17.84	4.9722	100.0	(0,0,2)
20.28	4.3797	66.1	(0,1,1)
20.33	4.3683	58.5	(0,1,-1)
23.40	3.8018	29.8	(1,0,2)
23.69	3.7557	3.3	(1,1,0)
25.33	3.5164	62.1	(1,1,1)
25.37	3.5105	61.8	(1,1,-1)
25.56	3.4851	8.0	(0,1,2)
25.65	3.4736	7.8	(0,1,-2)
29.78	3.0005	12.5	(1,1,2)
29.85	2.9932	9.8	(1,1,-2)
30.30	2.9494	99.7	(2,0,0)
32.63	2.7445	10.4	(0,1,3)
32.73	2.7362	9.1	(0,1,-3)
35.38	2.5367	4.1	(2,0,2)
36.10	2.4884	64.3	(1,1,3)
36.19	2.4821	68.5	(1,1,-3)
36.74	2.4464	21.1	(2,1,1)
36.77	2.4444	17.7	(2,1,-1)
36.91	2.4352	1.8	(0,2,0)
38.01	2.3671	9.4	(0,2,1)
38.07	2.3635	9.5	(0,2,-1)
39.33	2.2910	11.4	(1,0,4)
40.05	2.2514	7.7	(2,1,2)

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Energy Properties

Formation Energy/atom

-2.21543

eV/atom

Energy/atom

-7.71624

eV/atom

Energy above Hull

0.0590

eV/atom

Uncorrected Energy

-6.8704

eV/atom

Volume/atom

11.90

Å³

c/a Ratio

1.6859

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

4.0000

μB

Mag. Ordering

FiM

Mag. Sites

Magnetization/Volume

0.014000

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

0.9613

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

7.9921

J/mol·K

Ω Parameter

0.7513

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

34.815%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.6767

smaller = more stable mixing

VEC

4.917

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-4.125

kJ/mol; negative = exothermic mixing

Entropy Norm

0.6934

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (2)

aaabzixr aaadwqut

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-775017

Reference Citation

The crystal structure and related material properties of Fe3Ni(PO4)4 were obtained from the Materials Project database (MP-ID: mp-775017, 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_Fe3Ni(PO4)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.89884000
_cell_length_b   4.87037500
_cell_length_c   9.94453690
_cell_angle_alpha   89.81134978
_cell_angle_beta   90.00000000
_cell_angle_gamma   90.00000000
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Fe3Ni(PO4)4
_chemical_formula_sum   'Fe3 Ni1 P4 O16'
_cell_volume   285.70064951
_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
  Fe  Fe0  1  0.00000000  0.46804300  0.77331100  1.0
  Fe  Fe1  1  0.50000000  0.53381000  0.22662900  1.0
  Fe  Fe2  1  0.50000000  0.96731300  0.72542300  1.0
  Ni  Ni3  1  0.00000000  0.04846600  0.27734200  1.0
  P  P4  1  0.50000000  0.08295100  0.40318800  1.0
  P  P5  1  0.50000000  0.41621400  0.90433900  1.0
  P  P6  1  0.00000000  0.58244400  0.10195900  1.0
  P  P7  1  0.00000000  0.91838800  0.59298100  1.0
  O  O8  1  0.50000000  0.15268100  0.55302500  1.0
  O  O9  1  0.29914800  0.23366400  0.32850900  1.0
  O  O10  1  0.70085200  0.23366400  0.32850900  1.0
  O  O11  1  0.00000000  0.22778300  0.61700300  1.0
  O  O12  1  0.00000000  0.26763600  0.11497600  1.0
  O  O13  1  0.29707300  0.27115800  0.82858600  1.0
  O  O14  1  0.70292700  0.27115800  0.82858600  1.0
  O  O15  1  0.50000000  0.34639700  0.05328800  1.0
  O  O16  1  0.00000000  0.64394400  0.95002800  1.0
  O  O17  1  0.79487700  0.72327100  0.17318400  1.0
  O  O18  1  0.20512300  0.72327100  0.17318400  1.0
  O  O19  1  0.50000000  0.72629200  0.88082700  1.0
  O  O20  1  0.50000000  0.77450200  0.38222600  1.0
  O  O21  1  0.79762000  0.77161200  0.66919200  1.0
  O  O22  1  0.20238000  0.77161200  0.66919200  1.0
  O  O23  1  0.00000000  0.84372300  0.44451100  1.0

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