Fe2P2O9

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-1041062 · Space group: Pnma (#62)

Materials Project API

Basic Information

Formula

Fe2P2O9

MP-ID

mp-1041062

Elements

Sites

Density

2.9730

g/cm³

Volume

709.65

Å³

Cell a

6.4312

Cell b

7.8222

Cell c

14.1066

α Angle

90.04

β Angle

90.00

γ Angle

89.97

Space Group

Pnma

Point Group

mmm

Crystal System

Orthorhombic

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
12.55	7.0533	100.0	(0,0,2)
12.94	6.8431	13.7	(0,1,-1)
12.95	6.8386	13.7	(0,1,1)
16.92	5.2403	40.7	(0,1,-2)
16.93	5.2362	41.2	(0,1,2)
17.85	4.9689	20.2	(1,1,0)
17.86	4.9666	20.1	(1,-1,0)
18.93	4.6874	19.8	(1,1,-1)
18.94	4.6859	19.8	(1,1,1)
18.94	4.6854	19.8	(1,-1,1)
18.95	4.6840	19.7	(1,-1,-1)
21.88	4.0631	12.3	(1,1,-2)
21.88	4.0618	12.1	(1,-1,2)
21.89	4.0611	12.0	(1,1,2)
21.89	4.0600	12.1	(1,-1,-2)
22.05	4.0315	10.9	(0,1,-3)
22.06	4.0287	11.1	(0,1,3)
22.74	3.9111	11.4	(0,2,0)
23.60	3.7697	44.0	(0,2,-1)
23.61	3.7682	44.7	(0,2,1)
26.04	3.4216	7.8	(0,2,-2)
26.06	3.4193	7.6	(0,2,2)
27.42	3.2528	1.1	(1,2,-1)
27.43	3.2515	1.1	(1,-2,1)

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Energy Properties

Formation Energy/atom

-2.00702

eV/atom

Energy/atom

-7.56876

eV/atom

Energy above Hull

0.1637

eV/atom

Uncorrected Energy

-6.7461

eV/atom

Volume/atom

13.65

Å³

c/a Ratio

2.1935

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

35.8838

μB

Mag. Ordering

FiM

Mag. Sites

Magnetization/Volume

0.050570

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

O · 0.692

Element Family

Metalloid-Nonmetal

Solute Fraction

0.308

Interstitial Fraction

0.154

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

0.8305

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

6.9049

J/mol·K

Ω Parameter

0.6833

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

34.857%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.6675

smaller = more stable mixing

VEC

4.769

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-3.692

kJ/mol; negative = exothermic mixing

Entropy Norm

0.7560

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.498

Family

Interstitial Alloy

Matrix Element

O · 0.692

Related Tasks

Related computation task IDs (1)

aaaeggyl

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-1041062

Reference Citation

The crystal structure and related material properties of Fe2P2O9 were obtained from the Materials Project database (MP-ID: mp-1041062, 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_Fe2P2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.43118419
_cell_length_b   7.82219671
_cell_length_c   14.10661021
_cell_angle_alpha   90.04429155
_cell_angle_beta   90.00134844
_cell_angle_gamma   89.97288967
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Fe2P2O9
_chemical_formula_sum   'Fe8 P8 O36'
_cell_volume   709.64666993
_cell_formula_units_Z   4
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  0.75053200  0.34487900  0.87872300  1.0
  Fe  Fe1  1  0.24942100  0.65500100  0.12100300  1.0
  Fe  Fe2  1  0.24955800  0.84380600  0.62182300  1.0
  Fe  Fe3  1  0.75043500  0.15606000  0.37834300  1.0
  Fe  Fe4  1  0.49997000  0.99997700  0.99980800  1.0
  Fe  Fe5  1  0.49998900  0.49980900  0.50031300  1.0
  Fe  Fe6  1  0.00003000  0.49980600  0.50031300  1.0
  Fe  Fe7  1  0.00003800  0.99999100  0.99984200  1.0
  P  P8  1  0.25029300  0.35061200  0.93952200  1.0
  P  P9  1  0.74968400  0.64948900  0.05988000  1.0
  P  P10  1  0.74968700  0.85182600  0.55965800  1.0
  P  P11  1  0.25031900  0.14803800  0.44064700  1.0
  P  P12  1  0.74989300  0.39462600  0.68924200  1.0
  P  P13  1  0.75007500  0.10629500  0.18861500  1.0
  P  P14  1  0.24995100  0.89390500  0.81107300  1.0
  P  P15  1  0.25010900  0.60543300  0.31127500  1.0
  O  O16  1  0.05270800  0.58849100  0.37241600  1.0
  O  O17  1  0.55239200  0.41121400  0.62816300  1.0
  O  O18  1  0.94773300  0.08911300  0.12763500  1.0
  O  O19  1  0.44748100  0.91079600  0.87205600  1.0
  O  O20  1  0.94745200  0.41162300  0.62826600  1.0
  O  O21  1  0.44743600  0.58897200  0.37253100  1.0
  O  O22  1  0.05228300  0.91122500  0.87199600  1.0
  O  O23  1  0.55261500  0.08943500  0.12755300  1.0
  O  O24  1  0.25001700  0.33198400  0.48586600  1.0
  O  O25  1  0.75001400  0.66737100  0.51506400  1.0
  O  O26  1  0.75007800  0.83306000  0.01443500  1.0
  O  O27  1  0.25001000  0.16709600  0.98508100  1.0
  O  O28  1  0.75073500  0.14051600  0.95484400  1.0
  O  O29  1  0.24923100  0.85981400  0.04498600  1.0
  O  O30  1  0.24953500  0.63948300  0.54588100  1.0
  O  O31  1  0.75045400  0.35985900  0.45501300  1.0
  O  O32  1  0.75033000  0.22748100  0.74991300  1.0
  O  O33  1  0.24962600  0.77219900  0.25026900  1.0
  O  O34  1  0.24961200  0.72655700  0.75037700  1.0
  O  O35  1  0.75037600  0.27341600  0.24949100  1.0
  O  O36  1  0.44430400  0.13190000  0.37866600  1.0
  O  O37  1  0.94345500  0.86919000  0.62172500  1.0
  O  O38  1  0.55556800  0.63421400  0.12176000  1.0
  O  O39  1  0.05672100  0.36640400  0.87727300  1.0
  O  O40  1  0.55572500  0.86862500  0.62155300  1.0
  O  O41  1  0.05652000  0.13136800  0.37849600  1.0
  O  O42  1  0.44420500  0.36564300  0.87754600  1.0
  O  O43  1  0.94339700  0.63326000  0.12206900  1.0
  O  O44  1  0.74983800  0.51133600  0.98327000  1.0
  O  O45  1  0.24990100  0.02233100  0.72591200  1.0
  O  O46  1  0.25044700  0.47697100  0.22603200  1.0
  O  O47  1  0.74960600  0.52339900  0.77436100  1.0
  O  O48  1  0.74984600  0.98863700  0.48248700  1.0
  O  O49  1  0.25016100  0.01024100  0.51725700  1.0
  O  O50  1  0.25007800  0.48929300  0.01589200  1.0
  O  O51  1  0.75014100  0.97793200  0.27378500  1.0

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