LiNi2P2O9

High-Entropy Materials HEA

MP-ID: mp-1013987 · Space group: Pnma (#62)

Materials Project API

Basic Information

Formula

LiNi2P2O9

MP-ID

mp-1013987

Elements

Sites

Density

3.4026

g/cm³

Volume

644.72

Å³

Cell a

6.2576

Cell b

7.4375

Cell c

13.8529

α Angle

90.00

β Angle

90.00

γ Angle

90.00

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
12.78	6.9264	74.6	(0,0,2)
13.51	6.5528	27.6	(0,1,1)
17.50	5.0688	98.6	(0,1,2)
18.53	4.7883	43.4	(1,1,0)
19.11	4.6433	3.2	(1,0,2)
19.62	4.5255	58.4	(1,1,1)
22.57	3.9387	31.1	(1,1,2)
22.67	3.9230	30.9	(0,1,3)
23.93	3.7187	18.0	(0,2,0)
24.79	3.5916	100.0	(0,2,1)
26.82	3.3238	4.4	(1,1,3)
27.22	3.2764	15.3	(0,2,2)
28.43	3.1395	19.6	(0,1,4)
28.53	3.1288	25.7	(2,0,0)
30.80	2.9026	3.8	(1,2,2)
30.87	2.8963	32.8	(0,2,3)
31.37	2.8514	7.8	(2,0,2)
31.69	2.8235	95.1	(2,1,1)
31.89	2.8062	10.0	(1,1,4)
33.66	2.6624	24.7	(2,1,2)
34.55	2.5963	36.4	(0,1,5)
35.42	2.5344	17.1	(0,2,4)
36.74	2.4461	16.4	(2,1,3)
36.83	2.4404	28.5	(0,3,1)

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Energy Properties

Formation Energy/atom

-1.91594

eV/atom

Energy/atom

-6.83250

eV/atom

Energy above Hull

0.1434

eV/atom

Uncorrected Energy

-6.0279

eV/atom

Volume/atom

11.51

Å³

c/a Ratio

2.2138

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

7.7275

μB

Mag. Ordering

FiM

Mag. Sites

Magnetization/Volume

0.011990

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

O · 0.643

Element Family

Metalloid-Nonmetal

Solute Fraction

0.357

Interstitial Fraction

0.143

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

1.0285

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

8.5511

J/mol·K

Ω Parameter

0.4397

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

38.628%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.8135

smaller = more stable mixing

VEC

4.786

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-6.998

kJ/mol; negative = exothermic mixing

Entropy Norm

0.7419

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (2)

aaacfsdr aaaedoxv

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-1013987

Reference Citation

The crystal structure and related material properties of LiNi2P2O9 were obtained from the Materials Project database (MP-ID: mp-1013987, 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_LiNi2P2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.25759100
_cell_length_b   7.43748500
_cell_length_c   13.85284800
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   90.00000000
_symmetry_Int_Tables_number   1
_chemical_formula_structural   LiNi2P2O9
_chemical_formula_sum   'Li4 Ni8 P8 O36'
_cell_volume   644.72178593
_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
  Li  Li0  1  0.75000000  0.93935200  0.77799800  1.0
  Li  Li1  1  0.75000000  0.56064800  0.27799800  1.0
  Li  Li2  1  0.25000100  0.43935100  0.72200200  1.0
  Li  Li3  1  0.25000100  0.06064800  0.22200200  1.0
  Ni  Ni4  1  0.75000000  0.34793800  0.87989700  1.0
  Ni  Ni5  1  0.25000100  0.65206200  0.12010300  1.0
  Ni  Ni6  1  0.25000100  0.84793800  0.62010300  1.0
  Ni  Ni7  1  0.75000000  0.15206200  0.37989700  1.0
  Ni  Ni8  1  0.50000000  0.00000000  0.00000000  1.0
  Ni  Ni9  1  0.50000000  0.50000000  0.50000000  1.0
  Ni  Ni10  1  0.00000000  0.50000000  0.50000000  1.0
  Ni  Ni11  1  0.00000000  0.00000000  0.00000000  1.0
  P  P12  1  0.25000100  0.36254500  0.93504200  1.0
  P  P13  1  0.75000000  0.63745500  0.06495900  1.0
  P  P14  1  0.75000000  0.86254500  0.56495800  1.0
  P  P15  1  0.25000100  0.13745600  0.43504200  1.0
  P  P16  1  0.75000000  0.39912600  0.69624800  1.0
  P  P17  1  0.75000000  0.10087400  0.19624800  1.0
  P  P18  1  0.25000100  0.89912600  0.80375200  1.0
  P  P19  1  0.25000100  0.60087300  0.30375200  1.0
  O  O20  1  0.04277500  0.58061100  0.36204500  1.0
  O  O21  1  0.54277400  0.41938800  0.63795500  1.0
  O  O22  1  0.95722500  0.08061100  0.13795500  1.0
  O  O23  1  0.45722500  0.91938900  0.86204500  1.0
  O  O24  1  0.95722500  0.41938800  0.63795500  1.0
  O  O25  1  0.45722500  0.58061100  0.36204500  1.0
  O  O26  1  0.04277500  0.91938900  0.86204500  1.0
  O  O27  1  0.54277400  0.08061100  0.13795500  1.0
  O  O28  1  0.25000100  0.31427900  0.49385000  1.0
  O  O29  1  0.75000000  0.68572200  0.50615000  1.0
  O  O30  1  0.75000000  0.81427800  0.00614900  1.0
  O  O31  1  0.25000100  0.18572200  0.99385000  1.0
  O  O32  1  0.75000000  0.13573500  0.95633100  1.0
  O  O33  1  0.25000100  0.86426500  0.04366800  1.0
  O  O34  1  0.25000100  0.63573500  0.54366800  1.0
  O  O35  1  0.75000000  0.36426600  0.45633200  1.0
  O  O36  1  0.75000000  0.21872300  0.75512200  1.0
  O  O37  1  0.25000100  0.78127700  0.24487900  1.0
  O  O38  1  0.25000100  0.71872300  0.74487800  1.0
  O  O39  1  0.75000000  0.28127800  0.25512100  1.0
  O  O40  1  0.43798400  0.13589700  0.36225600  1.0
  O  O41  1  0.93798400  0.86410300  0.63774400  1.0
  O  O42  1  0.56201600  0.63589600  0.13774400  1.0
  O  O43  1  0.06201600  0.36410300  0.86225600  1.0
  O  O44  1  0.56201600  0.86410300  0.63774400  1.0
  O  O45  1  0.06201600  0.13589700  0.36225600  1.0
  O  O46  1  0.43798400  0.36410300  0.86225600  1.0
  O  O47  1  0.93798400  0.63589600  0.13774400  1.0
  O  O48  1  0.75000000  0.46914600  0.00238300  1.0
  O  O49  1  0.25000100  0.03787700  0.71728500  1.0
  O  O50  1  0.25000100  0.46212200  0.21728500  1.0
  O  O51  1  0.75000000  0.53787700  0.78271500  1.0
  O  O52  1  0.75000000  0.03085400  0.50238300  1.0
  O  O53  1  0.25000100  0.96914600  0.49761700  1.0
  O  O54  1  0.25000100  0.53085300  0.99761600  1.0
  O  O55  1  0.75000000  0.96212300  0.28271500  1.0

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