Rb2CoS2

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-8766 · Space group: Ibam (#72)

Materials Project API

Basic Information

Formula

Rb2CoS2

MP-ID

mp-8766

Elements

Sites

Density

3.4269

g/cm³

Volume

284.92

Å³

Cell a

8.1009

Cell b

8.1009

Cell c

8.1009

α Angle

135.81

β Angle

128.35

γ Angle

70.27

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
13.37	6.6249	14.0	(1,1,-1)
14.22	6.2292	19.6	(1,0,0)
23.50	3.7853	59.8	(1,1,0)
23.77	3.7439	74.2	(2,1,-1)
25.24	3.5289	6.2	(1,-1,1)
26.92	3.3124	26.1	(2,2,-2)
28.66	3.1146	12.4	(2,0,0)
29.31	3.0469	36.7	(1,-1,-1)
30.03	2.9758	100.0	(1,0,1)
32.34	2.7681	12.8	(0,2,0)
32.72	2.7370	27.5	(0,1,1)
33.30	2.6905	45.9	(2,2,-1)
35.75	2.5118	31.3	(2,1,0)
36.21	2.4808	2.1	(3,2,-2)
37.23	2.4151	30.8	(3,1,-1)
38.88	2.3164	13.5	(2,-1,1)
39.06	2.3062	34.8	(0,0,2)
40.21	2.2425	63.0	(1,3,-1)
40.86	2.2083	7.9	(3,3,-3)
41.46	2.1780	4.8	(1,1,1)
43.59	2.0764	5.5	(3,0,0)
45.31	2.0015	27.3	(3,2,-1)
45.54	1.9918	7.9	(3,3,-2)
47.25	1.9238	8.1	(2,3,-1)

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Energy Properties

Formation Energy/atom

-0.93991

eV/atom

Energy/atom

-4.41377

eV/atom

Energy above Hull

0.0476

eV/atom

Uncorrected Energy

-4.2126

eV/atom

Volume/atom

28.49

Å³

c/a Ratio

1.0000

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

6.0000

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.021060

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

Rb · 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

1.2637

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

38.452%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.7904

smaller = more stable mixing

VEC

4.600

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

4.400

kJ/mol; negative = exothermic mixing

Entropy Norm

0.9602

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.383

Family

Rb-rich Multi-Component

Matrix Element

Rb · 0.400

Related Tasks

Related computation task IDs (5)

aaadmyor aaadsqid aaaegime aaaetwsz aaafxair

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-8766

Reference Citation

The crystal structure and related material properties of Rb2CoS2 were obtained from the Materials Project database (MP-ID: mp-8766, 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_Rb2CoS2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.10093840
_cell_length_b   8.10093840
_cell_length_c   8.10093840
_cell_angle_alpha   135.81388635
_cell_angle_beta   128.35116834
_cell_angle_gamma   70.27176385
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Rb2CoS2
_chemical_formula_sum   'Rb4 Co2 S4'
_cell_volume   284.92279871
_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
  Rb  Rb0  1  0.68766000  0.35301500  0.33464500  1.0
  Rb  Rb1  1  0.01836900  0.85301500  0.16535500  1.0
  Rb  Rb2  1  0.31234000  0.64698500  0.66535500  1.0
  Rb  Rb3  1  0.98163100  0.14698500  0.83464500  1.0
  Co  Co4  1  0.50000000  0.25000000  0.75000000  1.0
  Co  Co5  1  0.50000000  0.75000000  0.25000000  1.0
  S  S6  1  0.23270900  0.40507600  0.82763300  1.0
  S  S7  1  0.57744300  0.90507600  0.67236700  1.0
  S  S8  1  0.76729100  0.59492400  0.17236700  1.0
  S  S9  1  0.42255700  0.09492400  0.32763300  1.0

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