FeAs2PbO8

High-Entropy Materials HEA

MP-ID: mp-818283 · Space group: P2_1/c (#14)

Materials Project API

Basic Information

Formula

FeAs2PbO8

MP-ID

mp-818283

Elements

Sites

Density

5.5045

g/cm³

Volume

652.67

Å³

Cell a

8.4695

Cell b

4.9472

Cell c

16.0967

α Angle

75.39

β Angle

90.00

γ Angle

90.00

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
11.89	7.4407	29.9	(1,0,1)
15.46	5.7329	12.4	(1,0,2)
18.53	4.7874	2.2	(0,1,0)
19.16	4.6328	28.6	(0,1,2)
20.06	4.4266	16.2	(1,0,3)
20.82	4.2667	29.9	(1,1,1)
20.98	4.2348	7.9	(2,0,0)
21.32	4.1676	6.2	(1,1,0)
22.84	3.8941	6.0	(0,0,4)
23.27	3.8220	4.7	(1,1,-1)
24.15	3.6849	71.8	(0,1,-2)
24.27	3.6667	18.3	(1,1,3)
25.17	3.5381	4.5	(1,0,4)
26.38	3.3790	5.5	(1,1,-2)
27.17	3.2817	1.2	(2,0,3)
27.71	3.2197	32.0	(1,1,4)
27.75	3.2149	8.6	(2,1,1)
28.13	3.1719	2.8	(2,1,0)
28.56	3.1257	100.0	(2,1,2)
29.67	3.0113	3.9	(2,1,-1)
30.30	2.9494	18.6	(1,1,-3)
30.58	2.9238	18.9	(1,0,5)
31.20	2.8664	74.1	(2,0,4)
32.20	2.7799	7.4	(2,1,-2)

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Energy Properties

Formation Energy/atom

-1.59315

eV/atom

Energy/atom

-6.68537

eV/atom

Energy above Hull

0.0691

eV/atom

Uncorrected Energy

-6.0394

eV/atom

Volume/atom

13.60

Å³

c/a Ratio

1.9006

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

20.0067

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.030650

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

O · 0.667

Element Family

Metalloid-Nonmetal

Solute Fraction

0.333

Interstitial Fraction

0.000

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

0.9831

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

8.1734

J/mol·K

Ω Parameter

6.1668

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

44.112%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.6266

smaller = more stable mixing

VEC

4.167

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

0.556

kJ/mol; negative = exothermic mixing

Entropy Norm

0.7091

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (2)

aaabuyia aaaeeeyt

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-818283

Reference Citation

The crystal structure and related material properties of FeAs2PbO8 were obtained from the Materials Project database (MP-ID: mp-818283, 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_FeAs2PbO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.46952400
_cell_length_b   4.94721800
_cell_length_c   16.09674223
_cell_angle_alpha   75.39452113
_cell_angle_beta   90.00000000
_cell_angle_gamma   90.00000000
_symmetry_Int_Tables_number   1
_chemical_formula_structural   FeAs2PbO8
_chemical_formula_sum   'Fe4 As8 Pb4 O32'
_cell_volume   652.66763539
_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  0.95098300  0.69256400  0.64649700  1.0
  Fe  Fe1  1  0.54901700  0.69256400  0.14649700  1.0
  Fe  Fe2  1  0.04901700  0.30743600  0.35350300  1.0
  Fe  Fe3  1  0.45098300  0.30743600  0.85350300  1.0
  As  As4  1  0.81035300  0.29580600  0.51879400  1.0
  As  As5  1  0.68964700  0.29580600  0.01879400  1.0
  As  As6  1  0.18964700  0.70419400  0.48120600  1.0
  As  As7  1  0.31035300  0.70419400  0.98120600  1.0
  As  As8  1  0.76742800  0.07146500  0.76680700  1.0
  As  As9  1  0.73257200  0.07146500  0.26680700  1.0
  As  As10  1  0.23257200  0.92853500  0.23319300  1.0
  As  As11  1  0.26742800  0.92853500  0.73319300  1.0
  Pb  Pb12  1  0.52762300  0.75231300  0.61860000  1.0
  Pb  Pb13  1  0.97237700  0.75231300  0.11860000  1.0
  Pb  Pb14  1  0.47237700  0.24768700  0.38140000  1.0
  Pb  Pb15  1  0.02762300  0.24768700  0.88140000  1.0
  O  O16  1  0.95161600  0.07640400  0.57284900  1.0
  O  O17  1  0.54838400  0.07640400  0.07284900  1.0
  O  O18  1  0.04838400  0.92359600  0.42715100  1.0
  O  O19  1  0.45161600  0.92359600  0.92715100  1.0
  O  O20  1  0.86519900  0.42036300  0.41421700  1.0
  O  O21  1  0.63480100  0.42036300  0.91421700  1.0
  O  O22  1  0.13480100  0.57963700  0.58578300  1.0
  O  O23  1  0.36519900  0.57963700  0.08578300  1.0
  O  O24  1  0.78135400  0.55926500  0.57230400  1.0
  O  O25  1  0.71864600  0.55926500  0.07230400  1.0
  O  O26  1  0.21864600  0.44073500  0.42769600  1.0
  O  O27  1  0.28135400  0.44073500  0.92769600  1.0
  O  O28  1  0.61949800  0.15659400  0.51817400  1.0
  O  O29  1  0.88050200  0.15659400  0.01817400  1.0
  O  O30  1  0.38050200  0.84340600  0.48182600  1.0
  O  O31  1  0.11949800  0.84340600  0.98182600  1.0
  O  O32  1  0.58832600  0.23782700  0.75895100  1.0
  O  O33  1  0.91167400  0.23782700  0.25895100  1.0
  O  O34  1  0.41167400  0.76217300  0.24104900  1.0
  O  O35  1  0.08832600  0.76217300  0.74104900  1.0
  O  O36  1  0.75206700  0.84487900  0.70065300  1.0
  O  O37  1  0.74793300  0.84487900  0.20065300  1.0
  O  O38  1  0.24793300  0.15512100  0.29934700  1.0
  O  O39  1  0.25206700  0.15512100  0.79934700  1.0
  O  O40  1  0.91594800  0.32325100  0.73491100  1.0
  O  O41  1  0.58405200  0.32325100  0.23491100  1.0
  O  O42  1  0.08405200  0.67674900  0.26508900  1.0
  O  O43  1  0.41594800  0.67674900  0.76508900  1.0
  O  O44  1  0.83720000  0.91340800  0.86710200  1.0
  O  O45  1  0.66280000  0.91340800  0.36710200  1.0
  O  O46  1  0.16280000  0.08659200  0.13289800  1.0
  O  O47  1  0.33720000  0.08659200  0.63289800  1.0

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