FeNi(PO4)2

High-Entropy Materials HEA

MP-ID: mp-780106 · Space group: R3 (#146)

Materials Project API

Basic Information

Formula

FeNi(PO4)2

MP-ID

mp-780106

Elements

Sites

Density

3.3943

g/cm³

Volume

446.87

Å³

Cell a

8.5155

Cell b

8.5155

Cell c

8.5155

α Angle

61.04

β Angle

61.04

γ Angle

61.04

Space Group

Point Group

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
14.60	6.0673	3.9	(1,1,0)
20.54	4.3246	97.9	(1,0,-1)
20.87	4.2567	6.6	(2,1,1)
20.87	4.2567	3.3	(1,1,2)
24.29	3.6640	100.0	(2,1,0)
25.29	3.5216	18.2	(2,0,0)
29.44	3.0337	8.1	(2,2,0)
31.91	2.8050	5.1	(2,-1,0)
31.91	2.8050	10.1	(2,0,-1)
32.80	2.7307	2.1	(2,-1,1)
32.80	2.7307	4.2	(2,1,-1)
33.23	2.6964	76.2	(3,2,1)
35.97	2.4968	45.2	(2,-1,-1)
36.17	2.4835	2.3	(3,1,0)
36.17	2.4835	1.2	(1,0,3)
36.76	2.4450	2.1	(3,3,2)
38.53	2.3367	1.2	(3,2,0)
41.77	2.1623	2.5	(2,0,-2)
42.47	2.1284	11.8	(4,2,2)
43.88	2.0633	1.5	(3,1,-1)
44.64	2.0301	4.2	(4,3,2)
44.81	2.0224	5.0	(4,1,1)
44.81	2.0224	2.5	(3,3,0)
47.62	1.9096	35.7	(4,3,1)

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Energy Properties

Formation Energy/atom

-2.12845

eV/atom

Energy/atom

-7.51718

eV/atom

Energy above Hull

0.0688

eV/atom

Uncorrected Energy

-6.6594

eV/atom

Volume/atom

12.41

Å³

c/a Ratio

1.0000

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

21.2257

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.047500

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

0.9831

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

8.1734

J/mol·K

Ω Parameter

0.8078

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

34.677%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.6713

smaller = more stable mixing

VEC

5.000

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-3.889

kJ/mol; negative = exothermic mixing

Entropy Norm

0.7091

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (3)

aaabumxw aaadrxbf aaadzqby

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-780106

Reference Citation

The crystal structure and related material properties of FeNi(PO4)2 were obtained from the Materials Project database (MP-ID: mp-780106, 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_FeNi(PO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.51549700
_cell_length_b   8.51549700
_cell_length_c   8.51549642
_cell_angle_alpha   61.04114736
_cell_angle_beta   61.04114736
_cell_angle_gamma   61.04115112
_symmetry_Int_Tables_number   1
_chemical_formula_structural   FeNi(PO4)2
_chemical_formula_sum   'Fe3 Ni3 P6 O24'
_cell_volume   446.86832032
_cell_formula_units_Z   3
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  0.64459500  0.64459500  0.64459500  1.0
  Fe  Fe1  1  0.85656100  0.85656100  0.85656100  1.0
  Fe  Fe2  1  0.35634200  0.35634200  0.35634200  1.0
  Ni  Ni3  1  0.00058000  0.00058000  0.00058000  1.0
  Ni  Ni4  1  0.14188100  0.14188100  0.14188100  1.0
  Ni  Ni5  1  0.50024500  0.50024500  0.50024500  1.0
  P  P6  1  0.95396200  0.24996000  0.54495100  1.0
  P  P7  1  0.54495100  0.95396200  0.24996000  1.0
  P  P8  1  0.24996000  0.54495100  0.95396200  1.0
  P  P9  1  0.75140300  0.45310800  0.04683000  1.0
  P  P10  1  0.45310800  0.04683000  0.75140300  1.0
  P  P11  1  0.04683000  0.75140300  0.45310800  1.0
  O  O12  1  0.50372800  0.11106800  0.31798200  1.0
  O  O13  1  0.31798200  0.50372800  0.11106800  1.0
  O  O14  1  0.11106800  0.31798200  0.50372800  1.0
  O  O15  1  0.93986600  0.09234400  0.74489500  1.0
  O  O16  1  0.98666700  0.18647300  0.38930500  1.0
  O  O17  1  0.75395300  0.40881000  0.56253400  1.0
  O  O18  1  0.74489500  0.93986600  0.09234400  1.0
  O  O19  1  0.56253400  0.75395300  0.40881000  1.0
  O  O20  1  0.82210800  0.60882200  0.00425300  1.0
  O  O21  1  0.40881000  0.56253400  0.75395300  1.0
  O  O22  1  0.90773400  0.25492300  0.05786800  1.0
  O  O23  1  0.60882200  0.00425300  0.82210800  1.0
  O  O24  1  0.38930500  0.98666700  0.18647300  1.0
  O  O25  1  0.09234400  0.74489500  0.93986600  1.0
  O  O26  1  0.59252600  0.44020900  0.24596500  1.0
  O  O27  1  0.18647300  0.38930500  0.98666700  1.0
  O  O28  1  0.44020900  0.24596500  0.59252600  1.0
  O  O29  1  0.25492300  0.05786800  0.90773400  1.0
  O  O30  1  0.24596500  0.59252600  0.44020900  1.0
  O  O31  1  0.00425300  0.82210800  0.60882200  1.0
  O  O32  1  0.05786800  0.90773400  0.25492300  1.0
  O  O33  1  0.89147700  0.67919100  0.49689300  1.0
  O  O34  1  0.67919100  0.49689300  0.89147700  1.0
  O  O35  1  0.49689300  0.89147700  0.67919100  1.0

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