Na2CoS2

High-Entropy Materials HEA Traditional Materials TRA Elasticity Data ELA

MP-ID: mp-8765 · Space group: Ibam (#72)

Materials Project API

Basic Information

Formula

Na2CoS2

MP-ID

mp-8765

Elements

Sites

Density

2.7657

g/cm³

Volume

202.98

Å³

Cell a

7.1134

Cell b

7.1134

Cell c

7.1134

α Angle

133.89

β Angle

126.78

γ Angle

73.02

Space Group

Ibam

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
15.50	5.7174	61.1	(1,1,-1)
15.92	5.5661	100.0	(1,0,0)
26.35	3.3819	10.1	(1,1,0)
27.26	3.2710	45.2	(2,1,-1)
31.29	2.8587	5.0	(2,2,-2)
32.13	2.7859	6.9	(1,-1,-1)
32.16	2.7831	14.9	(2,0,0)
33.33	2.6882	28.5	(1,0,1)
35.86	2.5044	13.2	(0,2,0)
36.05	2.4913	29.8	(0,1,1)
38.10	2.3622	10.2	(2,2,-1)
40.29	2.2385	11.9	(2,1,0)
41.97	2.1525	5.9	(3,2,-2)
42.49	2.1277	36.5	(3,1,-1)
42.63	2.1209	9.0	(1,2,0)
43.13	2.0972	38.0	(0,0,2)
43.33	2.0883	6.3	(2,-1,1)
45.46	1.9952	47.7	(1,3,-1)
46.10	1.9689	15.5	(1,1,1)
47.72	1.9058	2.6	(3,3,-3)
48.56	1.8749	7.5	(2,0,1)
49.10	1.8554	2.3	(3,0,0)
51.88	1.7625	6.7	(3,2,-1)
53.82	1.7033	10.8	(2,3,-1)

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Energy Properties

Formation Energy/atom

-0.81510

eV/atom

Energy/atom

-8.10124

eV/atom

Energy above Hull

0.1306

eV/atom

Uncorrected Energy

-4.2999

eV/atom

Volume/atom

20.30

Å³

c/a Ratio

1.0000

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

2.2119

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.010900

μB/Å³

Elastic Properties

K_VRH

95.995

GPa

G_VRH

695.709

GPa

Young's Modulus E

611.025

GPa

Poisson Ratio ν

-0.561

Pugh Ratio K/G

0.138

Vickers Hardness Est.

GPa

Ductility

Ductile

Anisotropy

186.881

Lame λ

-367.811

GPa

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

Na · 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

0.0667

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

26.977%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.7396

smaller = more stable mixing

VEC

4.600

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-86.466

kJ/mol; negative = exothermic mixing

Entropy Norm

0.9602

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.327

Family

Na-rich Multi-Component

Matrix Element

Na · 0.400

Elasticity Features

Elastic Modulus Comparison (GPa)

Elastic Features

Elastic Anisotropy A^U

186.8810

Homogeneous Poisson ν

-0.5610

Debye Temperature

1,824.4

Sound Velocity

16,720.5

m/s

Homogeneity

-0.5610

Related Tasks

Related computation task IDs (5)

aaadmzas aaadsxza aaaeaiuq aaaetzce aaafcdof

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-8765

Reference Citation

The crystal structure and related material properties of Na2CoS2 were obtained from the Materials Project database (MP-ID: mp-8765, 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_Na2CoS2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.11338048
_cell_length_b   7.11338048
_cell_length_c   7.11338048
_cell_angle_alpha   133.88703127
_cell_angle_beta   126.78358218
_cell_angle_gamma   73.02030129
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na2CoS2
_chemical_formula_sum   'Na4 Co2 S4'
_cell_volume   202.98493377
_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  0.51351600  0.85667500  0.65684100  1.0
  Na  Na1  1  0.80016700  0.64332500  0.15684100  1.0
  Na  Na2  1  0.48648400  0.14332500  0.34315900  1.0
  Na  Na3  1  0.19983300  0.35667500  0.84315900  1.0
  Co  Co4  1  0.00000000  0.25000000  0.25000000  1.0
  Co  Co5  1  0.00000000  0.75000000  0.75000000  1.0
  S  S6  1  0.90332100  0.10986900  0.79345200  1.0
  S  S7  1  0.31641700  0.60986900  0.70654800  1.0
  S  S8  1  0.09667900  0.89013100  0.20654800  1.0
  S  S9  1  0.68358300  0.39013100  0.29345200  1.0

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