Ni(RhO2)2

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-636519 · Space group: I4_1/amd (#141)

Materials Project API

Basic Information

Formula

Ni(RhO2)2

MP-ID

mp-636519

Elements

Sites

Density

6.8487

g/cm³

Volume

159.30

Å³

Cell a

5.9679

Cell b

6.1484

Cell c

5.9679

α Angle

119.02

β Angle

90.00

γ Angle

119.02

Space Group

I4_1/amd

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
17.87	4.9649	86.4	(1,0,0)
17.87	4.9649	86.4	(0,0,1)
17.87	4.9641	86.4	(0,1,-1)
17.87	4.9640	86.4	(1,-1,0)
29.09	3.0698	26.2	(1,0,1)
29.09	3.0695	26.2	(1,1,-1)
29.09	3.0694	26.2	(1,-1,-1)
29.10	3.0690	26.2	(1,-2,1)
29.94	2.9840	23.8	(0,1,-2)
29.95	2.9839	23.8	(2,-1,0)
33.60	2.6676	81.7	(1,1,0)
33.60	2.6676	81.7	(0,1,1)
33.60	2.6672	81.6	(0,2,-1)
33.60	2.6672	81.6	(1,-2,0)
35.09	2.5576	84.7	(2,0,-1)
35.09	2.5576	84.7	(2,-1,1)
35.09	2.5576	84.7	(1,-1,2)
35.09	2.5576	84.7	(1,0,-2)
35.09	2.5575	84.7	(1,1,-2)
35.09	2.5575	84.7	(2,-1,-1)
35.09	2.5573	84.7	(1,-2,2)
35.09	2.5573	84.7	(2,-2,1)
36.18	2.4825	71.3	(2,0,0)
36.18	2.4824	71.2	(0,0,2)

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Energy Properties

Formation Energy/atom

-1.04605

eV/atom

Energy/atom

-6.80327

eV/atom

Energy above Hull

0.0856

eV/atom

Uncorrected Energy

-6.0477

eV/atom

Volume/atom

11.38

Å³

c/a Ratio

1.0000

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

0.0000

μB

Mag. Ordering

AFM

Mag. Sites

Magnetization/Volume

0.000000

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

O · 0.571

Element Family

Metalloid-Nonmetal

Solute Fraction

0.429

Interstitial Fraction

0.000

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

0.9557

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

7.9457

J/mol·K

Ω Parameter

3.4597

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

38.884%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.6453

smaller = more stable mixing

VEC

6.286

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-2.107

kJ/mol; negative = exothermic mixing

Entropy Norm

0.8699

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.505

Family

O-rich Multi-Component

Matrix Element

O · 0.571

Related Tasks

Related computation task IDs (5)

aaacvdjt aaadmzjp aaadsuca aaaetyuz aaafcftk

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-636519

Reference Citation

The crystal structure and related material properties of Ni(RhO2)2 were obtained from the Materials Project database (MP-ID: mp-636519, 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…

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Raw CIF Data

# generated using pymatgen
data_Ni(RhO2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.96787122
_cell_length_b   6.14836507
_cell_length_c   5.96791536
_cell_angle_alpha   119.02436597
_cell_angle_beta   90.00320417
_cell_angle_gamma   119.02240357
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ni(RhO2)2
_chemical_formula_sum   'Ni2 Rh4 O8'
_cell_volume   159.29856812
_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
  Ni  Ni0  1  0.12504400  0.74999900  0.87495100  1.0
  Ni  Ni1  1  0.87502200  0.25000100  0.12498300  1.0
  Rh  Rh2  1  0.49999600  0.49993400  0.99991300  1.0
  Rh  Rh3  1  0.50000200  0.99998300  0.49996500  1.0
  Rh  Rh4  1  0.50003600  0.50001800  0.49999800  1.0
  Rh  Rh5  1  0.00008700  0.00006600  0.50000400  1.0
  O  O6  1  0.75887600  0.53725200  0.26865600  1.0
  O  O7  1  0.73126200  0.96260700  0.72156000  1.0
  O  O8  1  0.73133700  0.96274400  0.24112400  1.0
  O  O9  1  0.24109100  0.46262000  0.73135400  1.0
  O  O10  1  0.72151600  0.46263000  0.73136600  1.0
  O  O11  1  0.26863400  0.03736000  0.27848100  1.0
  O  O12  1  0.27844400  0.53740400  0.26873800  1.0
  O  O13  1  0.26865400  0.03738500  0.75890800  1.0

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