NbNi3(HC)2

High-Entropy Materials HEA

MP-ID: mp-1079801 · Space group: I4/mmm (#139)

Materials Project API

Basic Information

Formula

NbNi3(HC)2

MP-ID

mp-1079801

Elements

Sites

Density

7.0428

g/cm³

Volume

69.56

Å³

Cell a

4.8575

Cell b

4.8575

Cell c

4.8575

α Angle

127.74

β Angle

127.74

γ Angle

77.04

Space Group

I4/mmm

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 13)

2θ	d (Å)	I	hkl
23.41	3.8005	3.3	(1,1,-1)
23.87	3.7282	4.4	(1,0,-1)
38.02	2.3669	100.0	(2,0,-1)
41.42	2.1800	1.0	(2,1,-2)
42.25	2.1391	50.1	(1,-1,1)
47.87	1.9002	17.0	(2,2,-2)
48.86	1.8641	1.5	(2,0,-2)
49.10	1.8554	1.3	(2,-1,-1)
61.28	1.5126	15.3	(2,-2,0)
65.73	1.4206	24.3	(3,1,-3)
74.44	1.2745	26.0	(3,-1,-2)
81.30	1.1834	12.8	(4,0,-2)
82.56	1.1685	9.7	(3,3,-4)

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Energy Properties

Formation Energy/atom

0.20540

eV/atom

Energy/atom

-6.38135

eV/atom

Energy above Hull

0.4305

eV/atom

Uncorrected Energy

-6.3814

eV/atom

Volume/atom

8.70

Å³

c/a Ratio

1.0000

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Total Mag. Moment

0.0007

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.000010

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

Ni · 0.375

Element Family

3d-TM

Solute Fraction

0.625

Interstitial Fraction

0.250

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

1.3209

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

10.9819

J/mol·K

Ω Parameter

0.6444

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

48.601%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.3129

smaller = more stable mixing

VEC

5.625

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-33.250

kJ/mol; negative = exothermic mixing

Entropy Norm

0.9528

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (5)

aaadompd aaadwezd aaadyiny aaaesofk aaafbjkt

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-1079801

Reference Citation

The crystal structure and related material properties of NbNi3(HC)2 were obtained from the Materials Project database (MP-ID: mp-1079801, 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_NbNi3(HC)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.85746833
_cell_length_b   4.85746833
_cell_length_c   4.85746833
_cell_angle_alpha   127.74444866
_cell_angle_beta   127.74444866
_cell_angle_gamma   77.03937827
_symmetry_Int_Tables_number   1
_chemical_formula_structural   NbNi3(HC)2
_chemical_formula_sum   'Nb1 Ni3 H2 C2'
_cell_volume   69.56003496
_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
  Nb  Nb0  1  0.00000000  0.00000000  0.00000000  1.0
  Ni  Ni1  1  0.75000000  0.25000000  0.50000000  1.0
  Ni  Ni2  1  0.25000000  0.75000000  0.50000000  1.0
  Ni  Ni3  1  0.50000000  0.50000000  0.00000000  1.0
  H  H4  1  0.74341600  0.74341600  0.00000000  1.0
  H  H5  1  0.25658400  0.25658400  0.00000000  1.0
  C  C6  1  0.50000000  0.00000000  0.50000000  1.0
  C  C7  1  0.00000000  0.50000000  0.50000000  1.0

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