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HEAS Data Platform · Materials Science Database

FeAs2O7

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-1042861 · Space group: P2_1/c (#14)

Materials Project API

Basic Information

Formula
FeAs2O7
MP-ID
mp-1042861
Elements
3
Sites
40
Density
3.4020
g/cm³
Volume
620.25
ų
Cell a
7.1350
Å
Cell b
9.4374
Å
Cell c
9.5846
Å
α Angle
90.00
°
β Angle
106.04
°
γ Angle
90.00
°
Space Group
P2_1/c
Point Group
2/m
Crystal System
Monoclinic
Bravais Lattice
mP
Stability
No
Packing Fraction
-

X-ray Diffraction

Diffraction Pattern
X-axis: 2θ (°); Y-axis: relative intensity; Cu Kα ; λ=1.5418 Å
Diffraction Peaks (Top 24)
2θd (Å)Ihkl
12.91 6.8571 25.7 (1,0,0)
13.43 6.5919 34.2 (0,1,1)
15.98 5.5474 19.4 (1,1,0)
16.71 5.3052 8.4 (1,1,-1)
18.81 4.7187 85.9 (0,2,0)
19.27 4.6057 29.9 (0,0,2)
20.03 4.4320 44.2 (1,0,-2)
20.45 4.3424 76.3 (1,1,1)
21.15 4.1997 12.0 (0,2,1)
21.47 4.1391 4.4 (0,1,2)
22.16 4.0117 7.3 (1,1,-2)
22.88 3.8872 5.3 (1,2,0)
23.40 3.8011 3.5 (1,2,-1)
25.99 3.4286 14.2 (2,0,0)
26.12 3.4117 65.1 (1,0,2)
26.83 3.3226 4.1 (2,1,-1)
27.05 3.2959 3.9 (0,2,2)
27.61 3.2305 100.0 (1,2,-2)
27.68 3.2225 27.2 (2,1,0)
27.81 3.2085 9.1 (1,1,2)
27.82 3.2073 1.2 (2,0,-2)
29.41 3.0368 83.6 (2,1,-2)
29.95 2.9839 9.6 (1,1,-3)
30.02 2.9770 12.9 (0,3,1)
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Energy Properties

Formation Energy/atom
-1.40939
eV/atom
Energy/atom
-6.65399
eV/atom
Energy above Hull
0.1556
eV/atom
Uncorrected Energy
-5.9475
eV/atom
Volume/atom
15.51
ų
c/a Ratio
1.3433

Electronic Properties

Metallic
Metal
Band Gap
0
eV
Direct Gap
No
CBM
N/A
eV

Magnetic Properties

Magnetic
Yes
Total Mag. Moment
19.5847
μB
Mag. Ordering
FM
Mag. Sites
4
Magnetization/Volume
0.031580
μB/ų

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)
Composition Info
Major / Matrix Element
O · 0.700
Element Family
Metalloid-Nonmetal
Solute Fraction
0.300
Interstitial Fraction
0.000

High-Entropy Alloy Features

Composite Radar (normalized)
Element-Class Share
Mix Entropy ΔS/R
0.8018
HEA criterion (>1.0 = high entropy)
Mix Entropy ΔS
6.6663
J/mol·K
Ω Parameter
0.0000
Ω > 1.1 favors solid solution
Atomic Size Mismatch δr
34.838%
δr < 6.6% favors single-phase solid solution
Electronegativity Diff Δχ
0.6373
smaller = more stable mixing
VEC
4.200
valence electron concentration, affects phase stability
Mix Enthalpy ΔH_mix
0.000
kJ/mol; negative = exothermic mixing
Entropy Norm
0.7298
SS Former
0
Phase Tendency
IM

Traditional Material Features

ROM Blended-Feature Radar
Rating & Classification
Tier
B
Score
0.476
Family
O-rich Multi-Component
Matrix Element
O · 0.700

Related Tasks

Related computation task IDs (3)
aaachiva aaadrsln aaaecjig

Citation & References

Materials Project Page
https://materialsproject.org/materials/mp-1042861
Reference Citation

The crystal structure and related material properties of FeAs2O7 were obtained from the Materials Project database (MP-ID: mp-1042861, 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…

Style: Ball & Stick
Raw CIF Data 
# generated using pymatgen
data_FeAs2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.13499964
_cell_length_b   9.43740100
_cell_length_c   9.58460537
_cell_angle_alpha   90.00000000
_cell_angle_beta   106.04267554
_cell_angle_gamma   90.00000000
_symmetry_Int_Tables_number   1
_chemical_formula_structural   FeAs2O7
_chemical_formula_sum   'Fe4 As8 O28'
_cell_volume   620.25368394
_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  0.82032400  0.06865000  0.71448600  1.0
  Fe  Fe1  1  0.17967600  0.56865000  0.78551400  1.0
  Fe  Fe2  1  0.17967600  0.93135000  0.28551400  1.0
  Fe  Fe3  1  0.82032400  0.43135000  0.21448600  1.0
  As  As4  1  0.40949800  0.25758900  0.74409800  1.0
  As  As5  1  0.59050200  0.75758900  0.75590200  1.0
  As  As6  1  0.59050200  0.74241100  0.25590200  1.0
  As  As7  1  0.40949800  0.24241100  0.24409800  1.0
  As  As8  1  0.02199900  0.29732900  0.96285200  1.0
  As  As9  1  0.97800100  0.79732900  0.53714800  1.0
  As  As10  1  0.97800100  0.70267100  0.03714800  1.0
  As  As11  1  0.02199900  0.20267100  0.46285200  1.0
  O  O12  1  0.84263300  0.32261000  0.04563200  1.0
  O  O13  1  0.15736700  0.82261000  0.45436800  1.0
  O  O14  1  0.15736700  0.67739000  0.95436800  1.0
  O  O15  1  0.84263300  0.17739000  0.54563200  1.0
  O  O16  1  0.36788600  0.43501100  0.74437300  1.0
  O  O17  1  0.63211400  0.93501100  0.75562700  1.0
  O  O18  1  0.63211400  0.56498900  0.25562700  1.0
  O  O19  1  0.36788600  0.06498900  0.24437300  1.0
  O  O20  1  0.39009600  0.16254000  0.89377800  1.0
  O  O21  1  0.60990400  0.66254000  0.60622200  1.0
  O  O22  1  0.60990400  0.83746000  0.10622200  1.0
  O  O23  1  0.39009600  0.33746000  0.39377800  1.0
  O  O24  1  0.24690900  0.16821700  0.59537300  1.0
  O  O25  1  0.75309100  0.66821700  0.90462700  1.0
  O  O26  1  0.75309100  0.83178300  0.40462700  1.0
  O  O27  1  0.24690900  0.33178300  0.09537300  1.0
  O  O28  1  0.02475200  0.08640200  0.32852900  1.0
  O  O29  1  0.97524800  0.58640200  0.17147100  1.0
  O  O30  1  0.97524800  0.91359800  0.67147100  1.0
  O  O31  1  0.02475200  0.41359800  0.82852900  1.0
  O  O32  1  0.63809800  0.27387600  0.23041200  1.0
  O  O33  1  0.36190200  0.77387600  0.26958800  1.0
  O  O34  1  0.36190200  0.72612400  0.76958800  1.0
  O  O35  1  0.63809800  0.22612400  0.73041200  1.0
  O  O36  1  0.01645600  0.37155500  0.39332600  1.0
  O  O37  1  0.98354400  0.87155500  0.10667400  1.0
  O  O38  1  0.98354400  0.62844500  0.60667400  1.0
  O  O39  1  0.01645600  0.12844500  0.89332600  1.0
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