FeCu(PO4)2

High-Entropy Materials HEA

MP-ID: mp-768377 · Space group: R3 (#146)

Materials Project API

Basic Information

Formula

FeCu(PO4)2

MP-ID

mp-768377

Elements

Sites

Density

3.4937

g/cm³

Volume

441.07

Å³

Cell a

8.5020

Cell b

8.5872

Cell c

8.5872

α Angle

60.00

β Angle

59.67

γ Angle

59.67

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
14.66	6.0414	3.8	(1,1,0)
20.69	4.2936	100.0	(1,2,1)
20.90	4.2506	8.8	(1,0,-1)
24.41	3.6464	15.9	(0,1,2)
24.41	3.6464	76.1	(1,1,-1)
25.45	3.4998	18.5	(0,2,0)
29.57	3.0207	5.6	(2,2,0)
29.57	3.0207	2.8	(2,0,2)
32.14	2.7853	15.1	(1,3,1)
33.02	2.7127	5.7	(2,3,1)
33.02	2.7127	1.2	(1,-1,2)
33.29	2.6910	25.8	(2,1,-1)
33.29	2.6910	51.7	(3,2,1)
36.24	2.4789	43.7	(2,3,3)
36.37	2.4705	1.8	(1,1,-2)
36.74	2.4460	1.7	(3,1,0)
42.09	2.1468	2.9	(2,4,2)
42.54	2.1253	7.4	(2,0,-2)
42.54	2.1253	3.7	(2,-2,0)
44.18	2.0500	1.8	(3,4,2)
44.66	2.0290	3.4	(3,1,-1)
45.02	2.0138	5.7	(1,0,-3)
45.02	2.0138	2.9	(3,0,3)
47.75	1.9047	11.5	(3,2,-1)

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Energy Properties

Formation Energy/atom

-2.03781

eV/atom

Energy/atom

-7.28647

eV/atom

Energy above Hull

0.0879

eV/atom

Uncorrected Energy

-6.6405

eV/atom

Volume/atom

12.25

Å³

c/a Ratio

1.0100

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

17.0003

μB

Mag. Ordering

FiM

Mag. Sites

Magnetization/Volume

0.038540

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

1.1184

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

35.237%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.6726

smaller = more stable mixing

VEC

5.083

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-2.583

kJ/mol; negative = exothermic mixing

Entropy Norm

0.7091

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (2)

aaabzfxn aaadzjxz

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-768377

Reference Citation

The crystal structure and related material properties of FeCu(PO4)2 were obtained from the Materials Project database (MP-ID: mp-768377, 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_FeCu(PO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.50202198
_cell_length_b   8.58714781
_cell_length_c   8.58714827
_cell_angle_alpha   59.99999500
_cell_angle_beta   59.66823832
_cell_angle_gamma   59.66822738
_symmetry_Int_Tables_number   1
_chemical_formula_structural   FeCu(PO4)2
_chemical_formula_sum   'Fe3 Cu3 P6 O24'
_cell_volume   441.07147370
_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  0.06636200  0.64454600  0.64454600  1.0
  Fe  Fe1  1  0.42995300  0.85668200  0.85668200  1.0
  Fe  Fe2  1  0.93149600  0.35616800  0.35616800  1.0
  Cu  Cu3  1  0.99757300  0.00080900  0.00080900  1.0
  Cu  Cu4  1  0.56941900  0.14352700  0.14352700  1.0
  Cu  Cu5  1  0.49848700  0.50050400  0.50050400  1.0
  P  P6  1  0.25039500  0.24963600  0.54390800  1.0
  P  P7  1  0.25039500  0.95606100  0.24963600  1.0
  P  P8  1  0.25039500  0.54390800  0.95606100  1.0
  P  P9  1  0.74824700  0.45641100  0.04507200  1.0
  P  P10  1  0.74824700  0.04507200  0.75027100  1.0
  P  P11  1  0.74824700  0.75027100  0.45641100  1.0
  O  O12  1  0.06777500  0.11365200  0.31466300  1.0
  O  O13  1  0.06777500  0.50391000  0.11365200  1.0
  O  O14  1  0.06777500  0.31466300  0.50391000  1.0
  O  O15  1  0.22625200  0.08744200  0.74277000  1.0
  O  O16  1  0.44027900  0.18794700  0.38816000  1.0
  O  O17  1  0.26975700  0.41182200  0.56194600  1.0
  O  O18  1  0.22625200  0.94353600  0.08744200  1.0
  O  O19  1  0.26975700  0.75647500  0.41182200  1.0
  O  O20  1  0.56509400  0.61380900  0.00617800  1.0
  O  O21  1  0.26975700  0.56194600  0.75647500  1.0
  O  O22  1  0.77576400  0.25824000  0.05240100  1.0
  O  O23  1  0.56509400  0.00617800  0.81491900  1.0
  O  O24  1  0.44027900  0.98361500  0.18794700  1.0
  O  O25  1  0.22625200  0.74277000  0.94353600  1.0
  O  O26  1  0.72641800  0.44096500  0.24392600  1.0
  O  O27  1  0.44027900  0.38816000  0.98361500  1.0
  O  O28  1  0.72641800  0.24392600  0.58868900  1.0
  O  O29  1  0.77576400  0.05240100  0.91359500  1.0
  O  O30  1  0.72641800  0.58868900  0.44096500  1.0
  O  O31  1  0.56509400  0.81491900  0.61380900  1.0
  O  O32  1  0.77576400  0.91359500  0.25824000  1.0
  O  O33  1  0.93225700  0.68230200  0.49666800  1.0
  O  O34  1  0.93225700  0.49666800  0.88877200  1.0
  O  O35  1  0.93225700  0.88877200  0.68230200  1.0

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