MnNiAs

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-1079845 · Space group: P-62m (#189)

Materials Project API

Basic Information

Formula

MnNiAs

MP-ID

mp-1079845

Elements

Sites

Density

7.6332

g/cm³

Volume

123.05

Å³

Cell a

6.1431

Cell b

6.1780

Cell c

3.7513

α Angle

90.00

β Angle

90.00

γ Angle

120.19

Space Group

P-62m

Point Group

-6m2

Crystal System

Hexagonal

Bravais Lattice

Stability

Yes

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 24)

2θ	d (Å)	I	hkl
16.60	5.3402	3.5	(1,-1,0)
16.60	5.3399	3.5	(0,1,0)
16.70	5.3097	3.3	(1,0,0)
23.72	3.7513	21.7	(0,0,1)
28.90	3.0890	12.1	(1,-2,0)
29.07	3.0715	13.0	(2,-1,0)
29.07	3.0713	13.0	(1,1,0)
29.09	3.0696	4.9	(1,-1,1)
29.09	3.0696	4.9	(0,1,1)
29.15	3.0638	4.9	(1,0,1)
33.56	2.6701	1.7	(2,-2,0)
33.56	2.6700	1.7	(0,2,0)
33.76	2.6549	1.9	(2,0,0)
37.72	2.3846	74.9	(1,-2,1)
37.86	2.3765	72.0	(2,-1,1)
37.86	2.3764	71.9	(1,1,1)
41.51	2.1753	99.2	(2,-2,1)
41.51	2.1752	99.1	(0,2,1)
41.68	2.1671	97.5	(2,0,1)
44.83	2.0217	17.7	(2,-3,0)
44.83	2.0217	17.7	(1,-3,0)
45.02	2.0135	18.7	(3,-2,0)
45.03	2.0134	18.7	(1,2,0)
45.14	2.0086	18.5	(3,-1,0)

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Energy Properties

Formation Energy/atom

-0.25288

eV/atom

Energy/atom

-6.79031

eV/atom

Energy above Hull

0.0000

eV/atom

Uncorrected Energy

-14.2247

eV/atom

Volume/atom

13.67

Å³

c/a Ratio

0.6107

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

3.5546

μB

Mag. Ordering

Unknown

Mag. Sites

Magnetization/Volume

0.028890

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

Mn · 0.333

Element Family

3d-TM

Solute Fraction

0.667

Interstitial Fraction

0.000

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

1.0986

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

9.1339

J/mol·K

Ω Parameter

3.7138

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

4.180%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.2581

smaller = more stable mixing

VEC

6.667

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-3.556

kJ/mol; negative = exothermic mixing

Entropy Norm

1.0000

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.555

Family

Mn-rich Multi-Component

Matrix Element

Mn · 0.333

Related Tasks

Related computation task IDs (5)

aaadmjej aaadsniy aaaekvmd aaaeuntt aaafjiss

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-1079845

Reference Citation

The crystal structure and related material properties of MnNiAs were obtained from the Materials Project database (MP-ID: mp-1079845, 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_MnNiAs
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.14306410
_cell_length_b   6.17802231
_cell_length_c   3.75125619
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   120.19218021
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MnNiAs
_chemical_formula_sum   'Mn3 Ni3 As3'
_cell_volume   123.05452481
_cell_formula_units_Z   3
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
  Mn  Mn0  1  0.41621841  0.41602060  0.50000000  1.0
  Mn  Mn1  1  0.58383546  0.99981579  0.50000000  1.0
  Mn  Mn2  1  0.00000950  0.58538786  0.50000000  1.0
  Ni  Ni3  1  0.75426132  0.75292318  0.00000000  1.0
  Ni  Ni4  1  0.24578134  -0.00130344  0.00000000  1.0
  Ni  Ni5  1  0.00001822  0.24576475  -0.00000000  1.0
  As  As6  1  0.66587640  0.33253820  -0.00000000  1.0
  As  As7  1  0.33406499  0.66653384  -0.00000000  1.0
  As  As8  1  -0.00006564  0.00231922  0.50000000  1.0

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