K4Fe2O7

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-765192 · Space group: Pmc2_1 (#26)

Materials Project API

Basic Information

Formula

K4Fe2O7

MP-ID

mp-765192

Elements

Sites

Density

2.4948

g/cm³

Volume

1,517.89

Å³

Cell a

6.0583

Cell b

10.5088

Cell c

23.8415

α Angle

90.00

β Angle

90.00

γ Angle

90.00

Space Group

Pmc2_1

Point Group

mm2

Crystal System

Orthorhombic

Bravais Lattice

Orthorhombic P

Stability

Packing Fraction

0.5240

X-ray Diffraction

Diffraction Pattern

Target / Radiation

X-axis: 2θ (°); Y-axis: relative intensity; CuKa ; λ=1.5406 Å

Diffraction Peaks (Top 24)

2θ	d (Å)	I	hkl
13.97	6.3387	3.9	(0,1,3)
16.41	5.4009	3.8	(1,0,2)
16.87	5.2544	5.4	(0,2,0)
16.89	5.2486	1.6	(1,1,0)
17.10	5.1845	1.2	(0,1,4)
17.28	5.1313	1.1	(0,2,1)
17.30	5.1259	3.0	(1,1,1)
20.26	4.3830	25.2	(0,2,3)
20.28	4.3797	51.8	(1,1,3)
20.91	4.2488	2.0	(1,0,4)
22.37	3.9736	37.9	(0,0,6)
23.62	3.7661	1.1	(1,2,2)
23.94	3.7168	1.6	(0,1,6)
25.08	3.5511	16.4	(1,2,3)
25.23	3.5293	1.2	(1,1,5)
26.52	3.3608	1.3	(0,3,2)
26.83	3.3227	2.9	(1,0,6)
27.53	3.2400	1.1	(0,1,7)
27.83	3.2054	3.0	(0,3,3)
28.16	3.1694	39.2	(0,2,6)
28.17	3.1681	71.3	(1,1,6)
29.45	3.0325	100.0	(1,3,0)
29.49	3.0292	59.9	(2,0,0)
31.87	2.8083	3.4	(1,2,6)

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Energy Properties

Formation Energy/atom

-1.38648

eV/atom

Energy/atom

-5.70196

eV/atom

Energy above Hull

0.1226

eV/atom

Uncorrected Energy

-4.9850

eV/atom

Volume/atom

19.46

Å³

c/a Ratio

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

36.0000

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.023720

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

O · 0.538

Element Family

Metalloid-Nonmetal

Solute Fraction

0.462

Interstitial Fraction

0.000

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

0.9840

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

8.1807

J/mol·K

Ω Parameter

0.0000

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

59.351%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

1.1833

smaller = more stable mixing

VEC

3.692

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

0.000

kJ/mol; negative = exothermic mixing

Entropy Norm

0.8956

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.379

Family

O-rich Multi-Component

Matrix Element

O · 0.538

Related Tasks

Related computation task IDs (1)

aaacxyyz

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-765192

Reference Citation

The crystal structure and related material properties of K4Fe2O7 were obtained from the Materials Project database (MP-ID: mp-765192, 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

BibTeX

@article{Horton2025,
  author  = {Horton, Matthew K. and Huck, Patrick and Yang, Ruo Xi and Munro, Jason M. and Dwaraknath, Shyam and Ganose, Alex M. and Kingsbury, Ryan S. and Wen, Mingjian and Shen, Jimmy X. and Mathis, Tyler S. and Kaplan, Aaron D. and Berket, Karlo and Riebesell, Janosh and George, Janine and Rosen, Andrew S. and Spotte-Smith, Evan W. C. and McDermott, Matthew J. and Cohen, Orion A. and Dunn, Alex and Kuner, Matthew C. and Rignanese, Gian-Marco and Petretto, Guido and Waroquiers, David and Griffin, Sinead M. and Neaton, Jeffrey B. and Chrzan, Daryl C. and Asta, Mark and Hautier, Geoffroy and Cholia, Shreyas and Ceder, Gerbrand and Ong, Shyue Ping and Jain, Anubhav and Persson, Kristin A.},
  title   = {Accelerated data-driven materials science with the Materials Project},
  journal = {Nature Materials},
  year    = {2025},
  volume  = {24},
  number  = {10},
  pages   = {1522--1532},
  month   = {oct},
  doi     = {10.1038/s41563-025-02272-0},
  issn    = {1476-4660},
  url     = {https://doi.org/10.1038/s41563-025-02272-0},
  abstract = {The Materials Project was launched formally in 2011 to drive materials discovery forwards through high-throughput computation and open data. More than a decade later, the Materials Project has become an indispensable tool used by more than 600,000 materials researchers around the world. This Perspective describes how the Materials Project, as a data platform and a software ecosystem, has helped to shape research in data-driven materials science. We cover how sustainable software and computational methods have accelerated materials design while becoming more open source and collaborative in nature. Next, we present cases where the Materials Project was used to understand and discover functional materials. We then describe our efforts to meet the needs of an expanding user base, through technical infrastructure updates ranging from data architecture and cloud resources to interactive web applications. Finally, we discuss opportunities to better aid the research community, with the vision that more accessible and easy-to-understand materials data will result in democratized materials knowledge and an increasingly collaborative community.}
}

3D Crystal Structure Rendering

Loading 3D structure…

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Raw CIF Data

# generated using pymatgen
data_K4Fe2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.05834400
_cell_length_b   10.50878600
_cell_length_c   23.84153900
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   90.00000000
_symmetry_Int_Tables_number   1
_chemical_formula_structural   K4Fe2O7
_chemical_formula_sum   'K24 Fe12 O42'
_cell_volume   1517.89162188
_cell_formula_units_Z   6
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
  K  K0  1  0.50000000  0.04580800  0.00532600  1.0
  K  K1  1  0.00000000  0.83944000  0.05164600  1.0
  K  K2  1  0.50000000  0.33436700  0.10308600  1.0
  K  K3  1  0.00000000  0.53632200  0.16472600  1.0
  K  K4  1  0.50000000  0.96009000  0.17046800  1.0
  K  K5  1  0.00000000  0.16906100  0.23085700  1.0
  K  K6  1  0.50000000  0.67094300  0.27376700  1.0
  K  K7  1  0.00000000  0.45779000  0.32822600  1.0
  K  K8  1  0.50000000  0.03947000  0.33454000  1.0
  K  K9  1  0.00000000  0.83345800  0.38788400  1.0
  K  K10  1  0.50000000  0.33122700  0.45312100  1.0
  K  K11  1  0.00000000  0.54049400  0.49639000  1.0
  K  K12  1  0.50000000  0.95419200  0.50532600  1.0
  K  K13  1  0.00000000  0.16056000  0.55164600  1.0
  K  K14  1  0.50000000  0.66563300  0.60308600  1.0
  K  K15  1  0.00000000  0.46367800  0.66472600  1.0
  K  K16  1  0.50000000  0.03991000  0.67046800  1.0
  K  K17  1  0.00000000  0.83093900  0.73085700  1.0
  K  K18  1  0.50000000  0.32905700  0.77376700  1.0
  K  K19  1  0.00000000  0.54221000  0.82822600  1.0
  K  K20  1  0.50000000  0.96053000  0.83454000  1.0
  K  K21  1  0.00000000  0.16654200  0.88788400  1.0
  K  K22  1  0.50000000  0.66877300  0.95312100  1.0
  K  K23  1  0.00000000  0.45950600  0.99639000  1.0
  Fe  Fe24  1  0.00000000  0.16681000  0.09183300  1.0
  Fe  Fe25  1  0.50000000  0.67472900  0.09040400  1.0
  Fe  Fe26  1  0.00000000  0.82702800  0.25791000  1.0
  Fe  Fe27  1  0.50000000  0.32703900  0.24110900  1.0
  Fe  Fe28  1  0.00000000  0.17160200  0.41061300  1.0
  Fe  Fe29  1  0.50000000  0.67242600  0.42325000  1.0
  Fe  Fe30  1  0.00000000  0.83319000  0.59183300  1.0
  Fe  Fe31  1  0.50000000  0.32527100  0.59040400  1.0
  Fe  Fe32  1  0.00000000  0.17297200  0.75791000  1.0
  Fe  Fe33  1  0.50000000  0.67296100  0.74110900  1.0
  Fe  Fe34  1  0.00000000  0.82839800  0.91061300  1.0
  Fe  Fe35  1  0.50000000  0.32757400  0.92325000  1.0
  O  O36  1  0.27508100  0.60402700  0.06457500  1.0
  O  O37  1  0.72491900  0.60402700  0.06457500  1.0
  O  O38  1  0.50000000  0.82430900  0.06686000  1.0
  O  O39  1  0.00000000  0.32610600  0.09294100  1.0
  O  O40  1  0.23667500  0.08596100  0.09394700  1.0
  O  O41  1  0.76332500  0.08596100  0.09394700  1.0
  O  O42  1  0.50000000  0.67110800  0.15916100  1.0
  O  O43  1  0.73973500  0.40472500  0.23937500  1.0
  O  O44  1  0.26026500  0.40472500  0.23937500  1.0
  O  O45  1  0.50000000  0.16846000  0.23785100  1.0
  O  O46  1  0.00000000  0.66867300  0.26282100  1.0
  O  O47  1  0.76098300  0.90496600  0.26187300  1.0
  O  O48  1  0.23901700  0.90496600  0.26187300  1.0
  O  O49  1  0.00000000  0.16761500  0.34182900  1.0
  O  O50  1  0.27421900  0.59999800  0.39926500  1.0
  O  O51  1  0.72578100  0.59999800  0.39926500  1.0
  O  O52  1  0.50000000  0.82349000  0.40139600  1.0
  O  O53  1  0.00000000  0.32218100  0.43339200  1.0
  O  O54  1  0.77552600  0.09878700  0.43578700  1.0
  O  O55  1  0.22447400  0.09878700  0.43578700  1.0
  O  O56  1  0.50000000  0.66968100  0.49251200  1.0
  O  O57  1  0.27508100  0.39597300  0.56457500  1.0
  O  O58  1  0.72491900  0.39597300  0.56457500  1.0
  O  O59  1  0.50000000  0.17569100  0.56686000  1.0
  O  O60  1  0.00000000  0.67389400  0.59294100  1.0
  O  O61  1  0.76332500  0.91403900  0.59394700  1.0
  O  O62  1  0.23667500  0.91403900  0.59394700  1.0
  O  O63  1  0.50000000  0.32889200  0.65916100  1.0
  O  O64  1  0.26026500  0.59527500  0.73937500  1.0
  O  O65  1  0.73973500  0.59527500  0.73937500  1.0
  O  O66  1  0.50000000  0.83154000  0.73785100  1.0
  O  O67  1  0.00000000  0.33132700  0.76282100  1.0
  O  O68  1  0.76098300  0.09503400  0.76187300  1.0
  O  O69  1  0.23901700  0.09503400  0.76187300  1.0
  O  O70  1  0.00000000  0.83238500  0.84182900  1.0
  O  O71  1  0.27421900  0.40000200  0.89926500  1.0
  O  O72  1  0.72578100  0.40000200  0.89926500  1.0
  O  O73  1  0.50000000  0.17651000  0.90139600  1.0
  O  O74  1  0.00000000  0.67781900  0.93339200  1.0
  O  O75  1  0.77552600  0.90121300  0.93578700  1.0
  O  O76  1  0.22447400  0.90121300  0.93578700  1.0
  O  O77  1  0.50000000  0.33031900  0.99251200  1.0

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