FeCu(PO4)2

High-Entropy Materials HEA

MP-ID: mp-775167 · Space group: P2_1/m (#11)

Materials Project API

Basic Information

Formula

FeCu(PO4)2

MP-ID

mp-775167

Elements

Sites

Density

3.4155

g/cm³

Volume

300.78

Å³

Cell a

5.9666

Cell b

5.0491

Cell c

10.0043

α Angle

86.36

β Angle

90.00

γ Angle

90.00

Space Group

P2_1/m

Point Group

2/m

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
8.86	9.9842	3.1	(0,0,1)
17.77	4.9921	65.2	(0,0,2)
19.22	4.6179	100.0	(0,1,1)
20.24	4.3878	26.9	(0,1,-1)
23.10	3.8497	4.2	(1,1,0)
23.23	3.8287	5.2	(1,0,2)
24.29	3.6646	28.5	(0,1,2)
24.37	3.6519	12.1	(1,1,1)
25.19	3.5349	41.7	(1,1,-1)
25.91	3.4389	7.2	(0,1,-2)
28.59	3.1227	24.5	(1,1,2)
29.95	2.9833	71.3	(2,0,0)
29.99	2.9795	14.4	(1,1,-2)
31.25	2.8618	21.5	(0,1,3)
33.19	2.6994	6.3	(0,1,-3)
34.77	2.5804	12.7	(1,1,3)
35.04	2.5609	2.9	(2,0,2)
35.83	2.5059	32.6	(2,1,1)
35.98	2.4960	2.1	(0,0,4)
36.21	2.4805	16.7	(0,2,1)
36.42	2.4671	6.6	(2,1,-1)
36.54	2.4594	37.9	(1,1,-3)
37.36	2.4069	14.3	(0,2,-1)
38.80	2.3210	3.3	(1,2,0)

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Energy Properties

Formation Energy/atom

-2.08638

eV/atom

Energy/atom

-7.33503

eV/atom

Energy above Hull

0.0393

eV/atom

Uncorrected Energy

-6.6890

eV/atom

Volume/atom

12.53

Å³

c/a Ratio

1.6767

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

10.0014

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.033250

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)

aaabzjag aaadyucc

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-775167

Reference Citation

The crystal structure and related material properties of FeCu(PO4)2 were obtained from the Materials Project database (MP-ID: mp-775167, 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   5.96661700
_cell_length_b   5.04909800
_cell_length_c   10.00434428
_cell_angle_alpha   86.36081138
_cell_angle_beta   90.00000000
_cell_angle_gamma   90.00000000
_symmetry_Int_Tables_number   1
_chemical_formula_structural   FeCu(PO4)2
_chemical_formula_sum   'Fe2 Cu2 P4 O16'
_cell_volume   300.78347462
_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  0.75000000  0.45908000  0.78260400  1.0
  Fe  Fe1  1  0.25000000  0.54092000  0.21739600  1.0
  Cu  Cu2  1  0.25000000  0.86756100  0.69617800  1.0
  Cu  Cu3  1  0.75000000  0.13243900  0.30382200  1.0
  P  P4  1  0.25000000  0.40311500  0.89573300  1.0
  P  P5  1  0.75000000  0.94156900  0.60180600  1.0
  P  P6  1  0.25000000  0.05843100  0.39819400  1.0
  P  P7  1  0.75000000  0.59688500  0.10426700  1.0
  O  O8  1  0.75000000  0.64323100  0.95090400  1.0
  O  O9  1  0.25000000  0.71358200  0.86732200  1.0
  O  O10  1  0.03953500  0.28405800  0.83166700  1.0
  O  O11  1  0.46046500  0.28405800  0.83166700  1.0
  O  O12  1  0.94397400  0.77128900  0.67351200  1.0
  O  O13  1  0.55602600  0.77128900  0.67351200  1.0
  O  O14  1  0.75000000  0.23509100  0.62388800  1.0
  O  O15  1  0.25000000  0.11010300  0.54879100  1.0
  O  O16  1  0.75000000  0.88989700  0.45120900  1.0
  O  O17  1  0.25000000  0.76490900  0.37611200  1.0
  O  O18  1  0.05602600  0.22871100  0.32648800  1.0
  O  O19  1  0.44397400  0.22871100  0.32648800  1.0
  O  O20  1  0.53953500  0.71594200  0.16833300  1.0
  O  O21  1  0.96046500  0.71594200  0.16833300  1.0
  O  O22  1  0.75000000  0.28641800  0.13267800  1.0
  O  O23  1  0.25000000  0.35676900  0.04909600  1.0

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