MnNiP2O9

High-Entropy Materials HEA

MP-ID: mp-1043595 · Space group: Pnma (#62)

Materials Project API

Basic Information

Formula

MnNiP2O9

MP-ID

mp-1043595

Elements

Sites

Density

3.1709

g/cm³

Volume

669.41

Å³

Cell a

6.2326

Cell b

7.7440

Cell c

13.8697

α Angle

90.05

β Angle

89.81

γ Angle

90.10

Space Group

Pnma

Point Group

mmm

Crystal System

Orthorhombic

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
12.77	6.9348	100.0	(0,0,2)
13.09	6.7640	16.9	(0,1,-1)
13.10	6.7589	17.7	(0,1,1)
17.16	5.1684	39.1	(0,1,-2)
17.17	5.1639	38.7	(0,1,2)
18.26	4.8595	16.8	(1,-1,0)
18.29	4.8512	16.8	(1,1,0)
19.34	4.5906	19.1	(1,-1,1)
19.37	4.5820	18.9	(1,1,1)
19.37	4.5817	19.1	(1,-1,-1)
19.40	4.5763	18.7	(1,1,-1)
22.31	3.9855	10.8	(1,-1,2)
22.34	3.9789	10.9	(1,1,2)
22.37	3.9739	10.8	(1,-1,-2)
22.39	3.9714	10.8	(1,1,-2)
22.39	3.9711	14.9	(0,1,-3)
22.41	3.9681	14.9	(0,1,3)
22.97	3.8720	13.1	(0,2,0)
23.85	3.7302	44.9	(0,2,-1)
23.87	3.7285	45.0	(0,2,1)
26.35	3.3820	9.7	(0,2,-2)
26.37	3.3795	9.8	(0,2,2)
28.19	3.1657	11.6	(0,1,-4)
28.21	3.1636	11.4	(0,1,4)

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Energy Properties

Formation Energy/atom

-1.93900

eV/atom

Energy/atom

-7.34705

eV/atom

Energy above Hull

0.1317

eV/atom

Uncorrected Energy

-6.5477

eV/atom

Volume/atom

12.87

Å³

c/a Ratio

2.2254

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

20.0036

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.029880

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

O · 0.692

Element Family

Metalloid-Nonmetal

Solute Fraction

0.308

Interstitial Fraction

0.154

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

0.9372

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

7.7915

J/mol·K

Ω Parameter

0.7485

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

34.724%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.6985

smaller = more stable mixing

VEC

4.846

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-3.503

kJ/mol; negative = exothermic mixing

Entropy Norm

0.6760

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (1)

aaaeggej

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-1043595

Reference Citation

The crystal structure and related material properties of MnNiP2O9 were obtained from the Materials Project database (MP-ID: mp-1043595, 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_MnNiP2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.23257393
_cell_length_b   7.74396770
_cell_length_c   13.86968482
_cell_angle_alpha   90.05062430
_cell_angle_beta   89.81177250
_cell_angle_gamma   90.10046274
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MnNiP2O9
_chemical_formula_sum   'Mn4 Ni4 P8 O36'
_cell_volume   669.41337458
_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
  Mn  Mn0  1  0.74971600  0.35245800  0.88012800  1.0
  Mn  Mn1  1  0.25028900  0.64767500  0.11984600  1.0
  Mn  Mn2  1  0.24950200  0.85388200  0.62021800  1.0
  Mn  Mn3  1  0.75049300  0.14625400  0.37986900  1.0
  Ni  Ni4  1  0.49983000  0.00025000  0.00020500  1.0
  Ni  Ni5  1  0.50017200  0.49968800  0.50000400  1.0
  Ni  Ni6  1  0.99987600  0.49968000  0.50001200  1.0
  Ni  Ni7  1  0.99991900  0.00019300  0.00014900  1.0
  P  P8  1  0.24929000  0.34981100  0.93795400  1.0
  P  P9  1  0.75068000  0.65058100  0.06187300  1.0
  P  P10  1  0.74979800  0.84941000  0.56169900  1.0
  P  P11  1  0.25021600  0.15030600  0.43799500  1.0
  P  P12  1  0.74975400  0.39097900  0.69159500  1.0
  P  P13  1  0.25036800  0.60889800  0.30849000  1.0
  P  P14  1  0.24955400  0.89273500  0.80881900  1.0
  P  P15  1  0.75040200  0.10724100  0.19151300  1.0
  O  O16  1  0.04595800  0.60113500  0.37015200  1.0
  O  O17  1  0.54593000  0.39845400  0.63033000  1.0
  O  O18  1  0.95519600  0.09924200  0.13007700  1.0
  O  O19  1  0.45347600  0.89978200  0.87006800  1.0
  O  O20  1  0.95412200  0.39845200  0.62997300  1.0
  O  O21  1  0.45424600  0.60124800  0.36979200  1.0
  O  O22  1  0.04497300  0.90019600  0.87048300  1.0
  O  O23  1  0.54644000  0.10075000  0.13034300  1.0
  O  O24  1  0.24991900  0.33604400  0.48123100  1.0
  O  O25  1  0.75013800  0.66352100  0.51871300  1.0
  O  O26  1  0.75102300  0.83622100  0.01859300  1.0
  O  O27  1  0.24867800  0.16423100  0.98137900  1.0
  O  O28  1  0.74892300  0.14859800  0.95256900  1.0
  O  O29  1  0.25091900  0.85182000  0.04766000  1.0
  O  O30  1  0.24993000  0.64923400  0.54827400  1.0
  O  O31  1  0.75006800  0.35054700  0.45167500  1.0
  O  O32  1  0.75007700  0.22590400  0.75797500  1.0
  O  O33  1  0.24990500  0.77406300  0.24216200  1.0
  O  O34  1  0.24801900  0.72754400  0.74236700  1.0
  O  O35  1  0.75211300  0.27247500  0.25787600  1.0
  O  O36  1  0.44672700  0.13411000  0.37062600  1.0
  O  O37  1  0.94553600  0.86694100  0.62885200  1.0
  O  O38  1  0.55370700  0.63514500  0.12917100  1.0
  O  O39  1  0.05375800  0.36577100  0.87059600  1.0
  O  O40  1  0.55333900  0.86644600  0.62900700  1.0
  O  O41  1  0.05439800  0.13369100  0.37078900  1.0
  O  O42  1  0.44628000  0.36510200  0.87070700  1.0
  O  O43  1  0.94632100  0.63453100  0.12918200  1.0
  O  O44  1  0.75006000  0.96625800  0.27280400  1.0
  O  O45  1  0.24984500  0.03366100  0.72750900  1.0
  O  O46  1  0.25030100  0.46773200  0.22695100  1.0
  O  O47  1  0.74983900  0.53205600  0.77296400  1.0
  O  O48  1  0.74988600  0.98583200  0.48319100  1.0
  O  O49  1  0.25007000  0.01270500  0.51583900  1.0
  O  O50  1  0.24978200  0.48744200  0.01597600  1.0
  O  O51  1  0.75023500  0.51307400  0.98377800  1.0

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