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Ni(HO)2

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-626794 · Space group: R-3m (#166)

Basic Information

Formula
Ni(HO)2
MP-ID
mp-626794
Elements
3
Sites
20
Density
2.4456
g/cm³
Volume
251.79
ų
Cell a
3.1570
Å
Cell b
10.9480
Å
Cell c
7.5062
Å
α Angle
96.93
°
β Angle
77.96
°
γ Angle
90.00
°
Space Group
R-3m
Point Group
-3m
Crystal System
Trigonal
Bravais Lattice
Trigonal R
Stability
No
Packing Fraction
0.7400

X-ray Diffraction

Diffraction Pattern
X-axis: 2θ (°); Y-axis: relative intensity; CuKa ; λ=1.5406 Å
Diffraction Peaks (Top 24)
2θd (Å)Ihkl
12.15 7.2850 100.0 (0,0,1)
24.44 3.6425 7.7 (0,0,2)
32.98 2.7161 1.7 (0,4,0)
33.01 2.7139 1.7 (1,2,0)
33.02 2.7130 1.6 (1,-2,1)
33.77 2.6544 5.1 (0,4,-1)
33.77 2.6542 5.1 (1,-2,0)
33.80 2.6523 5.2 (1,2,1)
37.02 2.4283 1.2 (0,0,3)
38.81 2.3205 6.3 (1,-2,-1)
38.84 2.3187 6.3 (0,4,-2)
38.86 2.3173 6.3 (1,2,2)
43.97 2.0592 1.3 (0,4,2)
44.00 2.0582 1.3 (1,2,-2)
44.06 2.0552 1.3 (1,-2,3)
46.97 1.9347 3.6 (1,-2,-2)
47.02 1.9326 3.5 (0,4,-3)
47.04 1.9318 3.5 (1,2,3)
53.64 1.7087 1.5 (0,4,3)
53.66 1.7081 1.5 (1,2,-3)
53.74 1.7057 1.5 (1,-2,4)
57.26 1.6089 1.3 (1,-2,-3)
57.33 1.6071 1.3 (0,4,-4)
57.35 1.6066 1.3 (1,2,4)
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Energy Properties

Formation Energy/atom
-1.22734
eV/atom
Energy/atom
-5.72061
eV/atom
Energy above Hull
0.0279
eV/atom
Uncorrected Energy
-4.9376
eV/atom
Volume/atom
12.59
ų
c/a Ratio
2.3777

Electronic Properties

Metallic
Metal
Band Gap
0
eV
Direct Gap
No
CBM
N/A
eV

Magnetic Properties

Magnetic
Yes
Total Mag. Moment
0.0000
μB
Mag. Ordering
AFM
Mag. Sites
4
Magnetization/Volume
0.000000
μB/ų

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)
Composition Info
Major / Matrix Element
H · 0.400
Element Family
Alkali-AlkEarth
Solute Fraction
0.600
Interstitial Fraction
0.000

High-Entropy Alloy Features

Composite Radar (normalized)
Element-Class Share
Mix Entropy ΔS/R
1.0549
HEA criterion (>1.0 = high entropy)
Mix Entropy ΔS
8.7706
J/mol·K
Ω Parameter
0.0000
Ω > 1.1 favors solid solution
Atomic Size Mismatch δr
61.502%
δr < 6.6% favors single-phase solid solution
Electronegativity Diff Δχ
0.6633
smaller = more stable mixing
VEC
4.000
valence electron concentration, affects phase stability
Mix Enthalpy ΔH_mix
0.000
kJ/mol; negative = exothermic mixing
Entropy Norm
0.9602
SS Former
0
Phase Tendency
IM

Traditional Material Features

ROM Blended-Feature Radar
Rating & Classification
Tier
C
Score
0.396
Family
H-rich Multi-Component
Matrix Element
H · 0.400

Related Tasks

Citation & References

Materials Project Page
https://materialsproject.org/materials/mp-626794
Reference Citation

The crystal structure and related material properties of Ni(HO)2 were obtained from the Materials Project database (MP-ID: mp-626794, 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

BibTeX
@article{Horton2025,
  author  = {Horton, Matthew K. and Huck, Patrick and Yang, Ruo Xi and Munro, Jason M. and Dwaraknath, Shyam and Ganose, Alex M. and Kingsbury, Ryan S. and Wen, Mingjian and Shen, Jimmy X. and Mathis, Tyler S. and Kaplan, Aaron D. and Berket, Karlo and Riebesell, Janosh and George, Janine and Rosen, Andrew S. and Spotte-Smith, Evan W. C. and McDermott, Matthew J. and Cohen, Orion A. and Dunn, Alex and Kuner, Matthew C. and Rignanese, Gian-Marco and Petretto, Guido and Waroquiers, David and Griffin, Sinead M. and Neaton, Jeffrey B. and Chrzan, Daryl C. and Asta, Mark and Hautier, Geoffroy and Cholia, Shreyas and Ceder, Gerbrand and Ong, Shyue Ping and Jain, Anubhav and Persson, Kristin A.},
  title   = {Accelerated data-driven materials science with the Materials Project},
  journal = {Nature Materials},
  year    = {2025},
  volume  = {24},
  number  = {10},
  pages   = {1522--1532},
  month   = {oct},
  doi     = {10.1038/s41563-025-02272-0},
  issn    = {1476-4660},
  url     = {https://doi.org/10.1038/s41563-025-02272-0},
  abstract = {The Materials Project was launched formally in 2011 to drive materials discovery forwards through high-throughput computation and open data. More than a decade later, the Materials Project has become an indispensable tool used by more than 600,000 materials researchers around the world. This Perspective describes how the Materials Project, as a data platform and a software ecosystem, has helped to shape research in data-driven materials science. We cover how sustainable software and computational methods have accelerated materials design while becoming more open source and collaborative in nature. Next, we present cases where the Materials Project was used to understand and discover functional materials. We then describe our efforts to meet the needs of an expanding user base, through technical infrastructure updates ranging from data architecture and cloud resources to interactive web applications. Finally, we discuss opportunities to better aid the research community, with the vision that more accessible and easy-to-understand materials data will result in democratized materials knowledge and an increasingly collaborative community.}
}

3D Crystal Structure Rendering

Loading 3D structure…

Style: Ball & Stick
Raw CIF Data
# generated using pymatgen
data_Ni(HO)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.15696910
_cell_length_b   10.94803314
_cell_length_c   7.50617571
_cell_angle_alpha   96.92525611
_cell_angle_beta   77.95798626
_cell_angle_gamma   90.00304583
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ni(HO)2
_chemical_formula_sum   'Ni4 H8 O8'
_cell_volume   251.78881048
_cell_formula_units_Z   4
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  0.50022600  0.74965000  0.00007000  1.0
  Ni  Ni1  1  0.00036400  0.50041200  0.00004900  1.0
  Ni  Ni2  1  0.49981500  0.24985100  0.00003600  1.0
  Ni  Ni3  1  0.99965600  0.00019600  0.99990100  1.0
  H  H4  1  0.63535100  0.89425100  0.72791300  1.0
  H  H5  1  0.13552700  0.64401600  0.72773000  1.0
  H  H6  1  0.63529300  0.39429000  0.72799800  1.0
  H  H7  1  0.13534800  0.14413400  0.72766500  1.0
  H  H8  1  0.86472800  0.85569200  0.27199000  1.0
  H  H9  1  0.36464300  0.60589200  0.27242000  1.0
  H  H10  1  0.86467400  0.35564800  0.27208600  1.0
  H  H11  1  0.36455800  0.10584700  0.27214500  1.0
  O  O12  1  0.56893200  0.90492400  0.86076200  1.0
  O  O13  1  0.06946200  0.65496600  0.86055400  1.0
  O  O14  1  0.56922900  0.40512900  0.86083400  1.0
  O  O15  1  0.06853300  0.15508500  0.86047600  1.0
  O  O16  1  0.93128300  0.84492400  0.13915200  1.0
  O  O17  1  0.43120800  0.59498500  0.13962500  1.0
  O  O18  1  0.93045000  0.34507900  0.13925000  1.0
  O  O19  1  0.43071900  0.09502800  0.13934600  1.0
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