Na7(FeO4)2

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-778606 · Space group: P2_1/c (#14)

Materials Project API

Basic Information

Formula

Na7(FeO4)2

MP-ID

mp-778606

Elements

Sites

Density

2.7561

g/cm³

Volume

965.46

Å³

Cell a

5.8012

Cell b

9.2267

Cell c

18.0408

α Angle

90.26

β Angle

91.07

γ Angle

89.78

Space Group

P2_1/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
9.81	9.0187	5.8	(0,0,2)
15.28	5.8001	6.6	(1,0,0)
17.57	5.0476	13.6	(0,1,-3)
17.64	5.0271	12.6	(0,1,3)
18.03	4.9203	79.8	(1,0,-2)
18.03	4.9188	1.2	(1,1,0)
18.34	4.8375	36.1	(1,0,2)
18.61	4.7676	7.5	(1,1,-1)
18.69	4.7467	8.0	(1,-1,-1)
19.24	4.6133	64.5	(0,2,0)
19.69	4.5094	47.9	(0,0,4)
19.84	4.4742	26.4	(0,2,-1)
19.89	4.4646	26.3	(0,2,1)
20.41	4.3517	95.4	(1,1,-2)
20.50	4.3314	94.3	(1,-1,-2)
20.73	4.2857	96.4	(1,1,2)
20.74	4.2830	96.1	(1,-1,2)
21.60	4.1145	5.6	(0,2,-2)
21.68	4.0997	5.1	(0,2,2)
21.90	4.0585	42.6	(0,1,-4)
21.98	4.0443	40.9	(0,1,4)
23.15	3.8415	5.0	(1,1,-3)
23.26	3.8245	4.5	(1,-1,-3)
24.27	3.6679	14.6	(0,2,-3)

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Energy Properties

Formation Energy/atom

-1.53461

eV/atom

Energy/atom

-5.41201

eV/atom

Energy above Hull

0.0617

eV/atom

Uncorrected Energy

-4.8233

eV/atom

Volume/atom

14.20

Å³

c/a Ratio

3.1098

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

27.9995

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.029000

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

O · 0.471

Element Family

Metalloid-Nonmetal

Solute Fraction

0.529

Interstitial Fraction

0.000

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

0.9718

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

8.0800

J/mol·K

Ω Parameter

5.8297

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

49.389%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

1.1847

smaller = more stable mixing

VEC

3.235

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

0.543

kJ/mol; negative = exothermic mixing

Entropy Norm

0.8846

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.400

Family

O-rich Multi-Component

Matrix Element

O · 0.471

Related Tasks

Related computation task IDs (1)

aaaebekl

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-778606

Reference Citation

The crystal structure and related material properties of Na7(FeO4)2 were obtained from the Materials Project database (MP-ID: mp-778606, 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_Na7(FeO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.80118761
_cell_length_b   9.22665565
_cell_length_c   18.04080455
_cell_angle_alpha   90.25849414
_cell_angle_beta   91.06937121
_cell_angle_gamma   89.77941705
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na7(FeO4)2
_chemical_formula_sum   'Na28 Fe8 O32'
_cell_volume   965.45931639
_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
  Na  Na0  1  0.09314000  0.15951900  0.88953400  1.0
  Na  Na1  1  0.12029100  0.99718500  0.71845300  1.0
  Na  Na2  1  0.09188300  0.33877400  0.38996300  1.0
  Na  Na3  1  0.22400900  0.80181400  0.86452400  1.0
  Na  Na4  1  0.12163700  0.50105100  0.21836500  1.0
  Na  Na5  1  0.17414200  0.10059200  0.53897500  1.0
  Na  Na6  1  0.22211900  0.69779000  0.36557500  1.0
  Na  Na7  1  0.17675200  0.39856400  0.03950300  1.0
  Na  Na8  1  0.27059700  0.44736400  0.54149300  1.0
  Na  Na9  1  0.42940600  0.45841200  0.86347900  1.0
  Na  Na10  1  0.39101100  0.66187800  0.68768500  1.0
  Na  Na11  1  0.27083700  0.05309200  0.04220600  1.0
  Na  Na12  1  0.43168000  0.04163900  0.36367900  1.0
  Na  Na13  1  0.39573900  0.84121200  0.18686900  1.0
  Na  Na14  1  0.60426100  0.15878800  0.81313100  1.0
  Na  Na15  1  0.56832000  0.95836100  0.63632100  1.0
  Na  Na16  1  0.72916300  0.94690800  0.95779400  1.0
  Na  Na17  1  0.60898900  0.33812200  0.31231500  1.0
  Na  Na18  1  0.57059400  0.54158800  0.13652100  1.0
  Na  Na19  1  0.72940300  0.55263600  0.45850700  1.0
  Na  Na20  1  0.82324800  0.60143600  0.96049700  1.0
  Na  Na21  1  0.77788100  0.30221000  0.63442500  1.0
  Na  Na22  1  0.82585800  0.89940800  0.46102500  1.0
  Na  Na23  1  0.87836300  0.49894900  0.78163500  1.0
  Na  Na24  1  0.77599100  0.19818600  0.13547600  1.0
  Na  Na25  1  0.90811700  0.66122600  0.61003700  1.0
  Na  Na26  1  0.87970900  0.00281500  0.28154700  1.0
  Na  Na27  1  0.90686000  0.84048100  0.11046600  1.0
  Fe  Fe28  1  0.28483100  0.32897500  0.70336700  1.0
  Fe  Fe29  1  0.28701500  0.78088000  0.52311000  1.0
  Fe  Fe30  1  0.28398900  0.17296200  0.20297100  1.0
  Fe  Fe31  1  0.28900600  0.71855800  0.02293700  1.0
  Fe  Fe32  1  0.71099400  0.28144200  0.97706300  1.0
  Fe  Fe33  1  0.71601100  0.82703800  0.79702900  1.0
  Fe  Fe34  1  0.71298500  0.21912000  0.47689000  1.0
  Fe  Fe35  1  0.71516900  0.67102500  0.29663300  1.0
  O  O36  1  0.09403400  0.85340400  0.98813700  1.0
  O  O37  1  0.11636800  0.47407600  0.66816600  1.0
  O  O38  1  0.13026000  0.24574100  0.77186000  1.0
  O  O39  1  0.09790500  0.64813700  0.48761200  1.0
  O  O40  1  0.20500600  0.86685200  0.60517100  1.0
  O  O41  1  0.11080300  0.02668400  0.16808400  1.0
  O  O42  1  0.11578300  0.25347200  0.27083300  1.0
  O  O43  1  0.24223200  0.58595200  0.95269900  1.0
  O  O44  1  0.20403900  0.63516200  0.10646100  1.0
  O  O45  1  0.24482200  0.91244900  0.45263100  1.0
  O  O46  1  0.35986900  0.18336000  0.64670500  1.0
  O  O47  1  0.36892800  0.31652400  0.14729400  1.0
  O  O48  1  0.45999300  0.18412800  0.94393000  1.0
  O  O49  1  0.45607500  0.91243000  0.76931200  1.0
  O  O50  1  0.54350100  0.41529000  0.73002100  1.0
  O  O51  1  0.53733500  0.68280700  0.55679800  1.0
  O  O52  1  0.46266500  0.31719300  0.44320200  1.0
  O  O53  1  0.45649900  0.58471000  0.26997900  1.0
  O  O54  1  0.54392500  0.08757000  0.23068800  1.0
  O  O55  1  0.54000700  0.81587200  0.05607000  1.0
  O  O56  1  0.63107200  0.68347600  0.85270600  1.0
  O  O57  1  0.64013100  0.81664000  0.35329500  1.0
  O  O58  1  0.75517800  0.08755100  0.54736900  1.0
  O  O59  1  0.79596100  0.36483800  0.89353900  1.0
  O  O60  1  0.75776800  0.41404800  0.04730100  1.0
  O  O61  1  0.88421700  0.74652800  0.72916700  1.0
  O  O62  1  0.88919700  0.97331600  0.83191600  1.0
  O  O63  1  0.79499400  0.13314800  0.39482900  1.0
  O  O64  1  0.90209500  0.35186300  0.51238800  1.0
  O  O65  1  0.86974000  0.75425900  0.22814000  1.0
  O  O66  1  0.88363200  0.52592400  0.33183400  1.0
  O  O67  1  0.90596600  0.14659600  0.01186300  1.0

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