Mg2NiH2

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-1078818 · Space group: P4_2/mnm (#136)

Materials Project API

Basic Information

Formula

Mg2NiH2

MP-ID

mp-1078818

Elements

Sites

Density

2.9060

g/cm³

Volume

124.93

Å³

Cell a

4.4296

Cell b

4.4296

Cell c

6.3673

α Angle

90.00

β Angle

90.00

γ Angle

90.00

Space Group

P4_2/mnm

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 18)

2θ	d (Å)	I	hkl
24.48	3.6362	100.0	(1,0,1)
28.03	3.1837	1.2	(0,0,2)
28.50	3.1322	1.5	(1,1,0)
40.40	2.2328	82.3	(1,1,2)
40.74	2.2148	38.4	(2,0,0)
47.50	1.9141	15.7	(1,0,3)
48.10	1.8915	30.2	(2,1,1)
57.93	1.5918	6.9	(0,0,4)
58.98	1.5661	13.0	(2,2,0)
64.33	1.4482	11.7	(2,1,3)
64.82	1.4384	5.7	(3,0,1)
73.23	1.2926	12.4	(2,0,4)
73.92	1.2821	24.5	(3,1,2)
78.08	1.2239	3.2	(1,0,5)
78.99	1.2121	3.1	(3,0,3)
79.45	1.2063	6.1	(3,2,1)
87.35	1.1164	7.8	(2,2,4)
88.24	1.1074	3.8	(4,0,0)

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Energy Properties

Formation Energy/atom

-0.17262

eV/atom

Energy/atom

-3.33890

eV/atom

Energy above Hull

0.1057

eV/atom

Uncorrected Energy

-3.2673

eV/atom

Volume/atom

12.49

Å³

c/a Ratio

1.4375

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Total Mag. Moment

0.0010

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

Mg · 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

0.9872

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

62.424%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.4028

smaller = more stable mixing

VEC

3.200

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-6.400

kJ/mol; negative = exothermic mixing

Entropy Norm

0.9602

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.509

Family

Mg-rich Multi-Component

Matrix Element

Mg · 0.400

Related Tasks

Related computation task IDs (1)

aaadyplk

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-1078818

Reference Citation

The crystal structure and related material properties of Mg2NiH2 were obtained from the Materials Project database (MP-ID: mp-1078818, 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_Mg2NiH2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.42955000
_cell_length_b   4.42955000
_cell_length_c   6.36730200
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   90.00000000
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Mg2NiH2
_chemical_formula_sum   'Mg4 Ni2 H4'
_cell_volume   124.93227988
_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
  Mg  Mg0  1  0.50000000  0.00000000  0.25000000  1.0
  Mg  Mg1  1  0.00000000  0.50000000  0.25000000  1.0
  Mg  Mg2  1  0.50000000  0.00000000  0.75000000  1.0
  Mg  Mg3  1  0.00000000  0.50000000  0.75000000  1.0
  Ni  Ni4  1  0.50000000  0.50000000  0.50000000  1.0
  Ni  Ni5  1  0.00000000  0.00000000  0.00000000  1.0
  H  H6  1  0.74598800  0.25401200  0.50000000  1.0
  H  H7  1  0.25401200  0.74598800  0.50000000  1.0
  H  H8  1  0.75401200  0.75401200  0.00000000  1.0
  H  H9  1  0.24598800  0.24598800  0.00000000  1.0

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