RbMg6FeO8

High-Entropy Materials HEA

MP-ID: mp-1032412 · Space group: P4/mmm (#123)

Materials Project API

Basic Information

Formula

RbMg6FeO8

MP-ID

mp-1032412

Elements

Sites

Density

3.8551

g/cm³

Volume

178.82

Å³

Cell a

8.9369

Cell b

4.4731

Cell c

4.4731

α Angle

90.00

β Angle

90.00

γ Angle

90.00

Space Group

P4/mmm

Point Group

4/mmm

Crystal System

Tetragonal

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
9.90	8.9369	45.8	(1,0,0)
19.85	4.4731	2.4	(0,1,0)
19.87	4.4685	16.7	(2,0,0)
22.22	4.0001	2.0	(1,1,0)
28.21	3.1630	13.0	(0,1,1)
28.23	3.1613	2.6	(2,1,0)
29.97	2.9817	23.5	(1,1,1)
30.00	2.9790	12.4	(3,0,0)
34.75	2.5817	46.7	(2,1,1)
36.23	2.4795	3.1	(3,1,0)
40.33	2.2366	100.0	(0,2,0)
40.37	2.2342	46.1	(4,0,0)
41.63	2.1697	6.1	(1,2,0)
41.65	2.1686	6.9	(3,1,1)
45.34	2.0000	7.4	(2,2,0)
49.95	1.8258	1.1	(2,2,1)
49.98	1.8249	4.8	(4,1,1)
51.07	1.7886	10.1	(3,2,0)
55.32	1.6607	1.7	(3,2,1)
58.35	1.5815	29.6	(0,2,2)
58.38	1.5807	54.7	(4,2,0)
59.34	1.5573	2.1	(1,2,2)
59.39	1.5561	4.5	(5,1,1)
62.28	1.4909	2.7	(2,2,2)

Get direct link

Energy Properties

Formation Energy/atom

-2.30614

eV/atom

Energy/atom

-5.98221

eV/atom

Energy above Hull

0.4157

eV/atom

Uncorrected Energy

-5.4977

eV/atom

Volume/atom

11.18

Å³

c/a Ratio

0.5005

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

5.0000

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.027960

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

O · 0.500

Element Family

Metalloid-Nonmetal

Solute Fraction

0.500

Interstitial Fraction

0.000

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

1.0610

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

8.8208

J/mol·K

Ω Parameter

11.9079

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

50.047%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

1.0780

smaller = more stable mixing

VEC

3.313

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

0.375

kJ/mol; negative = exothermic mixing

Entropy Norm

0.7653

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (2)

aaacgtge aaacgtjc

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-1032412

Reference Citation

The crystal structure and related material properties of RbMg6FeO8 were obtained from the Materials Project database (MP-ID: mp-1032412, 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 | Drag to rotate · Scroll to zoom · Right-click to pan

Raw CIF Data

# generated using pymatgen
data_RbMg6FeO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.93691432
_cell_length_b   4.47312768
_cell_length_c   4.47312768
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   90.00000000
_symmetry_Int_Tables_number   1
_chemical_formula_structural   RbMg6FeO8
_chemical_formula_sum   'Rb1 Mg6 Fe1 O8'
_cell_volume   178.81756793
_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
  Rb  Rb0  1  0.00000000  0.50000000  0.50000000  1.0
  Mg  Mg1  1  0.50000000  0.00000000  0.00000000  1.0
  Mg  Mg2  1  0.50000000  0.50000000  0.50000000  1.0
  Mg  Mg3  1  0.26459132  0.00000000  0.50000000  1.0
  Mg  Mg4  1  0.73540868  -0.00000000  0.50000000  1.0
  Mg  Mg5  1  0.26459132  0.50000000  0.00000000  1.0
  Mg  Mg6  1  0.73540868  0.50000000  -0.00000000  1.0
  Fe  Fe7  1  0.00000000  0.00000000  0.00000000  1.0
  O  O8  1  0.24948340  -0.00000000  -0.00000000  1.0
  O  O9  1  0.75051660  0.00000000  0.00000000  1.0
  O  O10  1  0.28141372  0.50000000  0.50000000  1.0
  O  O11  1  0.71858628  0.50000000  0.50000000  1.0
  O  O12  1  0.00000000  0.00000000  0.50000000  1.0
  O  O13  1  0.50000000  0.00000000  0.50000000  1.0
  O  O14  1  0.00000000  0.50000000  0.00000000  1.0
  O  O15  1  0.50000000  0.50000000  0.00000000  1.0

Get direct link