Li2Fe2(PO4)3

High-Entropy Materials HEA

MP-ID: mp-776769 · Space group: C2/c (#15)

Materials Project API

Basic Information

Formula

Li2Fe2(PO4)3

MP-ID

mp-776769

Elements

Sites

Density

2.8797

g/cm³

Volume

473.41

Å³

Cell a

8.7150

Cell b

8.7150

Cell c

8.7710

α Angle

59.84

β Angle

59.84

γ Angle

61.01

Space Group

C2/c

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
14.22	6.2291	59.3	(1,0,1)
14.52	6.1002	8.9	(1,1,0)
20.07	4.4240	15.0	(1,-1,0)
20.25	4.3855	36.3	(1,1,2)
20.37	4.3602	100.0	(1,0,-1)
20.39	4.3564	68.2	(2,1,1)
23.67	3.7585	93.0	(1,-1,1)
23.80	3.7389	84.7	(2,1,2)
24.08	3.6952	92.1	(2,1,0)
24.99	3.5629	8.0	(0,0,2)
25.02	3.5587	1.2	(2,2,2)
28.66	3.1145	86.2	(2,0,2)
29.28	3.0501	28.7	(2,2,0)
31.20	2.8668	16.3	(2,-1,0)
31.58	2.8327	12.2	(3,1,1)
31.68	2.8242	18.8	(3,2,2)
32.25	2.7760	30.0	(2,1,3)
32.26	2.7749	27.3	(1,-1,2)
32.28	2.7729	1.1	(3,1,2)
32.68	2.7403	22.6	(2,1,-1)
35.31	2.5417	16.6	(2,-1,-1)
35.32	2.5410	28.5	(3,0,1)
35.55	2.5256	17.5	(3,2,3)
35.76	2.5111	15.5	(3,1,0)

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Energy Properties

Formation Energy/atom

-2.38279

eV/atom

Energy/atom

-7.45541

eV/atom

Energy above Hull

0.0419

eV/atom

Uncorrected Energy

-6.7840

eV/atom

Volume/atom

12.46

Å³

c/a Ratio

1.0064

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

22.0002

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.046470

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

O · 0.632

Element Family

Metalloid-Nonmetal

Solute Fraction

0.368

Interstitial Fraction

0.158

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

1.0556

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

8.7765

J/mol·K

Ω Parameter

0.3141

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

39.992%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.8746

smaller = more stable mixing

VEC

4.263

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-9.027

kJ/mol; negative = exothermic mixing

Entropy Norm

0.7615

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (2)

aaabzkhp aaadzgcu

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-776769

Reference Citation

The crystal structure and related material properties of Li2Fe2(PO4)3 were obtained from the Materials Project database (MP-ID: mp-776769, 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

Loading 3D structure…

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Raw CIF Data

# generated using pymatgen
data_Li2Fe2(PO4)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.71495531
_cell_length_b   8.71495531
_cell_length_c   8.77100350
_cell_angle_alpha   59.84427936
_cell_angle_beta   59.84427936
_cell_angle_gamma   61.01245058
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Li2Fe2(PO4)3
_chemical_formula_sum   'Li4 Fe4 P6 O24'
_cell_volume   473.40791595
_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
  Li  Li0  1  0.68447800  0.82589300  0.44302200  1.0
  Li  Li1  1  0.17410700  0.31552200  0.05697800  1.0
  Li  Li2  1  0.82589300  0.68447800  0.94302200  1.0
  Li  Li3  1  0.31552200  0.17410700  0.55697800  1.0
  Fe  Fe4  1  0.85721600  0.36446200  0.42543300  1.0
  Fe  Fe5  1  0.63553800  0.14278400  0.07456700  1.0
  Fe  Fe6  1  0.36446200  0.85721600  0.92543300  1.0
  Fe  Fe7  1  0.14278400  0.63553800  0.57456700  1.0
  P  P8  1  0.96602400  0.03397600  0.25000000  1.0
  P  P9  1  0.03397600  0.96602400  0.75000000  1.0
  P  P10  1  0.54281400  0.74642000  0.24549000  1.0
  P  P11  1  0.25358000  0.45718600  0.25451000  1.0
  P  P12  1  0.74642000  0.54281400  0.74549000  1.0
  P  P13  1  0.45718600  0.25358000  0.75451000  1.0
  O  O14  1  0.86574600  0.99446400  0.92666600  1.0
  O  O15  1  0.69347800  0.37640700  0.91199500  1.0
  O  O16  1  0.94844200  0.21811400  0.25376100  1.0
  O  O17  1  0.46816500  0.19647400  0.94767100  1.0
  O  O18  1  0.99446400  0.86574600  0.42666600  1.0
  O  O19  1  0.78188600  0.05155800  0.24623900  1.0
  O  O20  1  0.73230800  0.58521700  0.23938200  1.0
  O  O21  1  0.56517400  0.90374000  0.26221500  1.0
  O  O22  1  0.41478300  0.26769200  0.26061800  1.0
  O  O23  1  0.80352600  0.53183500  0.55232900  1.0
  O  O24  1  0.90374000  0.56517400  0.76221500  1.0
  O  O25  1  0.62359300  0.30652200  0.58800500  1.0
  O  O26  1  0.37640700  0.69347800  0.41199500  1.0
  O  O27  1  0.09626000  0.43482600  0.23778500  1.0
  O  O28  1  0.19647400  0.46816500  0.44767100  1.0
  O  O29  1  0.58521700  0.73230800  0.73938200  1.0
  O  O30  1  0.43482600  0.09626000  0.73778500  1.0
  O  O31  1  0.26769200  0.41478300  0.76061800  1.0
  O  O32  1  0.21811400  0.94844200  0.75376100  1.0
  O  O33  1  0.00553600  0.13425400  0.57333400  1.0
  O  O34  1  0.53183500  0.80352600  0.05232900  1.0
  O  O35  1  0.05155800  0.78188600  0.74623900  1.0
  O  O36  1  0.30652200  0.62359300  0.08800500  1.0
  O  O37  1  0.13425400  0.00553600  0.07333400  1.0

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