HoMg(CoO3)2

High-Entropy Materials HEA

MP-ID: mp-1041115 · Space group: Pc (#7)

Materials Project API

Basic Information

Formula

HoMg(CoO3)2

MP-ID

mp-1041115

Elements

Sites

Density

6.3356

g/cm³

Volume

211.30

Å³

Cell a

5.5514

Cell b

5.1366

Cell c

8.8948

α Angle

56.42

β Angle

90.00

γ Angle

90.00

Space Group

Point Group

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
15.97	5.5514	13.9	(1,0,0)
19.98	4.4429	68.6	(1,0,1)
20.76	4.2792	43.2	(0,1,0)
21.34	4.1637	42.1	(0,1,2)
23.60	3.7694	2.1	(1,1,1)
24.02	3.7051	3.6	(0,0,2)
26.30	3.3892	22.1	(1,1,0)
26.76	3.3309	21.4	(1,1,2)
28.97	3.0818	12.2	(1,0,2)
32.25	2.7757	34.2	(2,0,0)
33.55	2.6711	100.0	(1,1,-1)
34.30	2.6144	87.3	(1,1,3)
34.51	2.5993	21.3	(2,0,1)
34.95	2.5672	42.1	(0,2,2)
36.81	2.4417	22.7	(2,1,1)
38.64	2.3301	3.9	(1,2,2)
38.67	2.3287	4.6	(2,1,0)
39.00	2.3095	4.9	(2,1,2)
39.95	2.2568	13.8	(1,0,3)
40.04	2.2517	8.6	(0,1,-2)
40.26	2.2399	19.2	(1,2,1)
40.91	2.2061	16.0	(1,2,3)
41.01	2.2009	8.7	(0,1,4)
42.24	2.1396	3.4	(0,2,0)

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Energy Properties

Formation Energy/atom

-2.15099

eV/atom

Energy/atom

-7.16927

eV/atom

Energy above Hull

0.1407

eV/atom

Uncorrected Energy

-6.4295

eV/atom

Volume/atom

10.57

Å³

c/a Ratio

1.6023

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

2.0001

μB

Mag. Ordering

FiM

Mag. Sites

Magnetization/Volume

0.009470

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

O · 0.600

Element Family

Metalloid-Nonmetal

Solute Fraction

0.400

Interstitial Fraction

0.000

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

1.0889

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

9.0531

J/mol·K

Ω Parameter

2.4691

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

47.054%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.9340

smaller = more stable mixing

VEC

5.500

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-2.391

kJ/mol; negative = exothermic mixing

Entropy Norm

0.7855

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (2)

aaachgdd aaaeacef

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-1041115

Reference Citation

The crystal structure and related material properties of HoMg(CoO3)2 were obtained from the Materials Project database (MP-ID: mp-1041115, 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

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Raw CIF Data

# generated using pymatgen
data_HoMg(CoO3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.55135900
_cell_length_b   5.13655200
_cell_length_c   8.89478906
_cell_angle_alpha   56.41800277
_cell_angle_beta   90.00000000
_cell_angle_gamma   90.00000000
_symmetry_Int_Tables_number   1
_chemical_formula_structural   HoMg(CoO3)2
_chemical_formula_sum   'Ho2 Mg2 Co4 O12'
_cell_volume   211.30084087
_cell_formula_units_Z   2
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
  Ho  Ho0  1  0.16701700  0.72469900  0.25341000  1.0
  Ho  Ho1  1  0.83298300  0.72469900  0.75341000  1.0
  Mg  Mg2  1  0.67661600  0.27844600  0.24656100  1.0
  Mg  Mg3  1  0.32338400  0.27844600  0.74656100  1.0
  Co  Co4  1  0.73796300  0.99693700  0.00219200  1.0
  Co  Co5  1  0.74038100  0.49577500  0.49963600  1.0
  Co  Co6  1  0.26203700  0.99693700  0.50219200  1.0
  Co  Co7  1  0.25961900  0.49577500  0.99963600  1.0
  O  O8  1  0.70138400  0.12644800  0.76331000  1.0
  O  O9  1  0.43578700  0.72562200  0.06404400  1.0
  O  O10  1  0.44314300  0.36172400  0.43801300  1.0
  O  O11  1  0.92774700  0.63157500  0.05838500  1.0
  O  O12  1  0.92181100  0.26108900  0.43725300  1.0
  O  O13  1  0.22008800  0.89954700  0.73507500  1.0
  O  O14  1  0.29861600  0.12644800  0.26331000  1.0
  O  O15  1  0.56421300  0.72562200  0.56404400  1.0
  O  O16  1  0.55685700  0.36172400  0.93801300  1.0
  O  O17  1  0.07818900  0.26108900  0.93725300  1.0
  O  O18  1  0.07225300  0.63157500  0.55838500  1.0
  O  O19  1  0.77991200  0.89954700  0.23507500  1.0

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