NaNO2

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-675369 · Space group: P2_1/m (#11)

Materials Project API

Basic Information

Formula

NaNO2

MP-ID

mp-675369

Elements

Sites

Density

1.7603

g/cm³

Volume

130.17

Å³

Cell a

4.9981

Cell b

4.5441

Cell c

5.7448

α Angle

86.11

β Angle

90.00

γ Angle

90.00

Space Group

P2_1/m

Point Group

2/m

Crystal System

Monoclinic

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
15.46	5.7315	96.3	(0,0,1)
23.62	3.7670	100.0	(1,0,1)
24.19	3.6793	17.9	(0,1,1)
25.87	3.4437	22.8	(0,1,-1)
26.54	3.3580	21.4	(1,1,0)
30.16	2.9630	3.0	(1,1,1)
31.55	2.8358	1.0	(1,1,-1)
35.94	2.4990	21.6	(2,0,0)
36.13	2.4861	99.8	(1,0,2)
39.77	2.2668	67.4	(0,2,0)
40.33	2.2361	19.1	(1,1,2)
41.85	2.1586	8.5	(0,2,1)
42.49	2.1276	14.7	(1,1,-2)
43.79	2.0673	4.6	(2,1,1)
43.94	2.0606	5.8	(0,2,-1)
44.81	2.0226	3.1	(2,1,-1)
45.79	1.9817	15.6	(1,2,1)
47.60	1.9105	16.1	(0,0,3)
47.74	1.9051	10.9	(1,2,-1)
48.32	1.8835	5.0	(2,0,2)
51.19	1.7846	3.1	(1,0,3)
51.72	1.7675	13.4	(2,1,2)
53.04	1.7264	24.4	(1,2,2)
53.51	1.7125	13.6	(2,1,-2)

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Energy Properties

Formation Energy/atom

0.66822

eV/atom

Energy/atom

-4.22576

eV/atom

Energy above Hull

1.9128

eV/atom

Uncorrected Energy

-4.1453

eV/atom

Volume/atom

16.27

Å³

c/a Ratio

1.1494

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

4.0000

μB

Mag. Ordering

FiM

Mag. Sites

Magnetization/Volume

0.030730

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

O · 0.500

Element Family

Metalloid-Nonmetal

Solute Fraction

0.500

Interstitial Fraction

0.250

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

1.0397

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

8.6442

J/mol·K

Ω Parameter

0.0405

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

55.382%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

1.0420

smaller = more stable mixing

VEC

3.500

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-29.017

kJ/mol; negative = exothermic mixing

Entropy Norm

0.9464

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.269

Family

Interstitial Alloy

Matrix Element

O · 0.500

Related Tasks

Related computation task IDs (4)

aaadoeiy aaadvwmz aaadwvzs aaaeqfnm

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-675369

Reference Citation

The crystal structure and related material properties of NaNO2 were obtained from the Materials Project database (MP-ID: mp-675369, 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_NaNO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.99806300
_cell_length_b   4.54404900
_cell_length_c   5.74475388
_cell_angle_alpha   86.10665884
_cell_angle_beta   90.00000000
_cell_angle_gamma   90.00000000
_symmetry_Int_Tables_number   1
_chemical_formula_structural   NaNO2
_chemical_formula_sum   'Na2 N2 O4'
_cell_volume   130.17054572
_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
  Na  Na0  1  0.25000000  0.25201600  0.39868300  1.0
  Na  Na1  1  0.75000000  0.74798400  0.60131700  1.0
  N  N2  1  0.25000000  0.26975500  0.94535900  1.0
  N  N3  1  0.75000000  0.73024500  0.05464100  1.0
  O  O4  1  0.38490300  0.75650700  0.34024900  1.0
  O  O5  1  0.11509700  0.75650700  0.34024900  1.0
  O  O6  1  0.61509700  0.24349300  0.65975100  1.0
  O  O7  1  0.88490300  0.24349300  0.65975100  1.0

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