Ba8Fe8O21

高熵材料 HEA 传统材料 TRA

MP-ID: mp-879789 · Space group: P-1 (#2)

Materials Project API

Basic Information

Formula

Ba8Fe8O21

MP-ID

mp-879789

Elements

Sites

Density

5.7424

g/cm³

Volume

544.04

Å³

Cell a

5.7442

Cell b

5.7831

Cell c

19.0404

α Angle

97.62

β Angle

90.67

γ Angle

119.40

Space Group

P-1

Point Group

-1

Crystal System

Triclinic

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
14.13	6.2659	1.4	(0,0,3)
17.83	4.9746	1.5	(0,1,0)
18.00	4.9280	20.8	(1,0,-1)
22.05	4.0306	14.7	(1,-1,3)
23.89	3.7240	100.0	(0,1,-4)
28.12	3.1738	6.7	(0,1,4)
30.82	2.9009	56.3	(1,-1,-5)
32.21	2.7792	48.4	(1,-2,-1)
32.70	2.7383	44.7	(2,-1,2)
36.11	2.4873	16.7	(0,2,0)
36.16	2.4840	36.3	(1,1,3)
36.47	2.4640	59.5	(2,0,-2)
36.50	2.4617	4.9	(1,1,-5)
38.15	2.3593	14.0	(2,-2,-2)
38.31	2.3497	13.4	(0,0,8)
39.51	2.2810	27.5	(1,0,7)
42.47	2.1284	2.7	(2,-1,-6)
43.01	2.1028	2.6	(1,-2,7)
44.98	2.0153	32.8	(2,-2,6)
45.58	1.9904	17.4	(1,0,-9)
47.80	1.9029	14.8	(1,2,-1)
48.40	1.8805	1.8	(2,-3,2)
48.54	1.8754	15.4	(1,-3,3)
48.66	1.8712	6.7	(2,0,6)

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Energy Properties

Formation Energy/atom

-0.99601

eV/atom

Energy/atom

-6.05058

eV/atom

Energy above Hull

1.2659

eV/atom

Uncorrected Energy

-5.1729

eV/atom

Volume/atom

14.70

Å³

c/a Ratio

3.3147

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

33.5289

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.061630

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

O · 0.568

Element Family

Metalloid-Nonmetal

Solute Fraction

0.432

Interstitial Fraction

0.000

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

0.9837

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

8.1787

J/mol·K

Ω Parameter

0.0000

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

57.591%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

1.0758

smaller = more stable mixing

VEC

4.432

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

0.000

kJ/mol; negative = exothermic mixing

Entropy Norm

0.8954

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (1)

aaabybmb

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-879789

Reference Citation

The crystal structure and related material properties of Ba8Fe8O21 were obtained from the Materials Project database (MP-ID: mp-879789, 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_Ba8Fe8O21
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.74417800
_cell_length_b   5.78308913
_cell_length_c   19.04038149
_cell_angle_alpha   97.62177524
_cell_angle_beta   90.66556253
_cell_angle_gamma   119.39564278
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ba8Fe8O21
_chemical_formula_sum   'Ba8 Fe8 O21'
_cell_volume   544.04174090
_cell_formula_units_Z   1
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
  Ba  Ba0  1  0.62040800  0.99720400  0.12698600  1.0
  Ba  Ba1  1  0.50000000  0.50000000  0.00000000  1.0
  Ba  Ba2  1  0.37959200  0.00279600  0.87301400  1.0
  Ba  Ba3  1  0.00000000  0.50000000  0.50000000  1.0
  Ba  Ba4  1  0.87578600  0.99647100  0.37179100  1.0
  Ba  Ba5  1  0.75381800  0.50203200  0.24635600  1.0
  Ba  Ba6  1  0.24618200  0.49796800  0.75364400  1.0
  Ba  Ba7  1  0.12421400  0.00352900  0.62820900  1.0
  Fe  Fe8  1  0.99614800  0.28449700  0.93082700  1.0
  Fe  Fe9  1  0.29772200  0.70735500  0.30437000  1.0
  Fe  Fe10  1  0.00385200  0.71550300  0.06917300  1.0
  Fe  Fe11  1  0.17146900  0.23612300  0.18627000  1.0
  Fe  Fe12  1  0.70227800  0.29264500  0.69563000  1.0
  Fe  Fe13  1  0.44224600  0.27120800  0.44361200  1.0
  Fe  Fe14  1  0.55775400  0.72879200  0.55638800  1.0
  Fe  Fe15  1  0.82853100  0.76387700  0.81373000  1.0
  O  O16  1  0.40162100  0.52111800  0.87307600  1.0
  O  O17  1  0.00000000  0.00000000  0.00000000  1.0
  O  O18  1  0.85948200  0.47491000  0.88262000  1.0
  O  O19  1  0.00000000  0.50000000  0.00000000  1.0
  O  O20  1  0.12235700  0.99312100  0.12342300  1.0
  O  O21  1  0.87764300  0.00687900  0.87657700  1.0
  O  O22  1  0.24812300  0.98848100  0.25855100  1.0
  O  O23  1  0.14051800  0.52509000  0.11738000  1.0
  O  O24  1  0.73955800  0.99347400  0.25077900  1.0
  O  O25  1  0.59837900  0.47888200  0.12692400  1.0
  O  O26  1  0.50000000  0.50000000  0.50000000  1.0
  O  O27  1  0.23558300  0.47869900  0.24730000  1.0
  O  O28  1  0.50000000  0.00000000  0.50000000  1.0
  O  O29  1  0.00000000  0.00000000  0.50000000  1.0
  O  O30  1  0.13896300  0.52023800  0.62438400  1.0
  O  O31  1  0.86103700  0.47976200  0.37561600  1.0
  O  O32  1  0.36980400  0.49509500  0.37447800  1.0
  O  O33  1  0.63019600  0.50490500  0.62552200  1.0
  O  O34  1  0.76441700  0.52130100  0.75270000  1.0
  O  O35  1  0.26044200  0.00652600  0.74922100  1.0
  O  O36  1  0.75187700  0.01151900  0.74144900  1.0

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