Ho2CoOs

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-864696 · Space group: Fm-3m (#225)

Materials Project API

Basic Information

Formula

Ho2CoOs

MP-ID

mp-864696

Elements

Sites

Density

12.5086

g/cm³

Volume

76.87

Å³

Cell a

4.7726

Cell b

4.7726

Cell c

4.7726

α Angle

60.00

β Angle

60.00

γ Angle

60.00

Space Group

Fm-3m

Point Group

m-3m

Crystal System

Cubic

Bravais Lattice

Stability

Packing Fraction

0.7405

X-ray Diffraction

Diffraction Pattern

Target / Radiation

X-axis: 2θ (°); Y-axis: relative intensity; Cu Kα ; λ=1.5418 Å

Diffraction Peaks (Top 10)

2θ	d (Å)	I	hkl
22.82	3.8968	10.9	(1,1,1)
26.41	3.3747	2.3	(1,1,0)
37.70	2.3863	100.0	(2,1,1)
44.52	2.0350	6.0	(2,2,1)
54.37	1.6874	17.4	(2,2,0)
59.72	1.5484	2.7	(3,2,2)
68.05	1.3777	35.3	(3,3,2)
72.81	1.2989	2.0	(3,3,3)
80.50	1.1931	11.1	(4,2,2)
85.02	1.1409	2.1	(4,3,2)

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Energy Properties

Formation Energy/atom

-0.14224

eV/atom

Energy/atom

-7.03128

eV/atom

Energy above Hull

0.1115

eV/atom

Uncorrected Energy

-7.0313

eV/atom

Volume/atom

19.22

Å³

c/a Ratio

1.0000

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

0.8532

μB

Mag. Ordering

FiM

Mag. Sites

Magnetization/Volume

0.011100

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

Ho · 0.500

Element Family

Lanthanide

Solute Fraction

0.500

Interstitial Fraction

0.000

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

1.0397

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

8.6442

J/mol·K

Ω Parameter

5.8303

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

14.935%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.4205

smaller = more stable mixing

VEC

9.750

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-3.166

kJ/mol; negative = exothermic mixing

Entropy Norm

0.9464

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.434

Family

Ho-rich Multi-Component

Matrix Element

Ho · 0.500

Related Tasks

Related computation task IDs (5)

aaachvhu aaadchtf aaaduoar aaaetioq aaafxetv

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-864696

Reference Citation

The crystal structure and related material properties of Ho2CoOs were obtained from the Materials Project database (MP-ID: mp-864696, 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_Ho2CoOs
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.77255075
_cell_length_b   4.77255075
_cell_length_c   4.77255075
_cell_angle_alpha   60.00000000
_cell_angle_beta   60.00000000
_cell_angle_gamma   60.00000000
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ho2CoOs
_chemical_formula_sum   'Ho2 Co1 Os1'
_cell_volume   76.86642244
_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
  Ho  Ho0  1  0.75000000  0.75000000  0.75000000  1.0
  Ho  Ho1  1  0.25000000  0.25000000  0.25000000  1.0
  Co  Co2  1  0.00000000  0.00000000  0.00000000  1.0
  Os  Os3  1  0.50000000  0.50000000  0.50000000  1.0

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