Er2NiOs

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-867344 · Space group: Fm-3m (#225)

Materials Project API

Basic Information

Formula

Er2NiOs

MP-ID

mp-867344

Elements

Sites

Density

12.9608

g/cm³

Volume

74.75

Å³

Cell a

4.7284

Cell b

4.7284

Cell c

4.7284

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 20)

2θ	d (Å)	I	hkl
23.04	3.8607	3.8	(0,0,1)
23.04	3.8607	11.4	(1,0,0)
26.66	3.3435	1.2	(1,0,1)
26.66	3.3435	2.3	(1,1,0)
38.06	2.3642	50.0	(0,1,-1)
38.06	2.3642	100.0	(2,1,1)
44.96	2.0162	6.2	(1,1,-1)
44.96	2.0162	1.4	(2,1,0)
54.92	1.6717	8.7	(2,0,2)
54.92	1.6717	17.3	(2,2,0)
60.34	1.5341	1.5	(1,0,-2)
60.34	1.5341	1.5	(3,1,1)
62.07	1.4952	1.2	(2,1,-1)
68.78	1.3650	4.4	(1,0,3)
68.78	1.3650	26.4	(1,1,-2)
68.78	1.3650	22.0	(3,1,0)
73.60	1.2869	1.2	(3,0,2)
81.41	1.1821	5.6	(0,2,-2)
81.41	1.1821	11.1	(4,2,2)
86.01	1.1303	1.2	(3,-1,1)

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Energy Properties

Formation Energy/atom

-0.35607

eV/atom

Energy/atom

-6.89180

eV/atom

Energy above Hull

0.0479

eV/atom

Uncorrected Energy

-33.5982

eV/atom

Volume/atom

18.69

Å³

c/a Ratio

1.0000

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

0.3200

μB

Mag. Ordering

Unknown

Mag. Sites

Magnetization/Volume

0.004280

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

Er · 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

6.3285

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

15.159%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.4202

smaller = more stable mixing

VEC

10.500

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-2.950

kJ/mol; negative = exothermic mixing

Entropy Norm

0.9464

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.477

Family

Er-rich Multi-Component

Matrix Element

Er · 0.500

Related Tasks

Related computation task IDs (5)

aaadnxbv aaadwlmx aaaeguja aaaetfhq aaafxenq

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-867344

Reference Citation

The crystal structure and related material properties of Er2NiOs were obtained from the Materials Project database (MP-ID: mp-867344, 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_Er2NiOs
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.72834705
_cell_length_b   4.72834706
_cell_length_c   4.72834778
_cell_angle_alpha   60.00000514
_cell_angle_beta   59.99999490
_cell_angle_gamma   59.99999995
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Er2NiOs
_chemical_formula_sum   'Er2 Ni1 Os1'
_cell_volume   74.75032864
_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
  Er  Er0  1  0.00000000  0.00000000  0.00000000  1.0
  Er  Er1  1  0.49999900  0.49999900  0.50000000  1.0
  Ni  Ni2  1  0.25000000  0.25000000  0.25000000  1.0
  Os  Os3  1  0.75000000  0.75000000  0.75000000  1.0

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