Cs2CoSe2

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-8770 · Space group: Ibam (#72)

Materials Project API

Basic Information

Formula

Cs2CoSe2

MP-ID

mp-8770

Elements

Sites

Density

4.4152

g/cm³

Volume

363.06

Å³

Cell a

8.8068

Cell b

8.8068

Cell c

8.8068

α Angle

135.67

β Angle

129.17

γ Angle

69.70

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
12.25	7.2274	11.2	(1,1,-1)
13.22	6.6984	17.3	(1,0,0)
21.64	4.1069	28.8	(1,1,0)
21.88	4.0630	39.6	(2,1,-1)
23.54	3.7795	16.2	(1,-1,1)
24.64	3.6137	40.5	(2,2,-2)
26.62	3.3492	4.6	(2,0,0)
26.83	3.3228	57.9	(1,-1,-1)
27.85	3.2036	100.0	(1,0,1)
29.59	3.0190	2.9	(0,2,0)
30.02	2.9767	6.1	(0,1,1)
30.54	2.9270	61.5	(2,2,-1)
33.00	2.7144	51.5	(2,1,0)
34.33	2.6119	27.2	(3,1,-1)
34.88	2.5722	1.2	(1,2,0)
35.99	2.4955	33.7	(0,0,2)
36.19	2.4822	3.0	(2,-1,1)
36.74	2.4460	60.4	(1,3,-1)
37.33	2.4091	1.6	(3,3,-3)
38.15	2.3589	2.1	(1,1,1)
40.40	2.2328	6.9	(3,0,0)
41.61	2.1703	16.5	(3,2,-1)
41.63	2.1696	8.1	(3,3,-2)
43.17	2.0955	7.8	(2,3,-1)

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Energy Properties

Formation Energy/atom

-0.90071

eV/atom

Energy/atom

-4.08895

eV/atom

Energy above Hull

0.0213

eV/atom

Uncorrected Energy

-3.9002

eV/atom

Volume/atom

36.31

Å³

c/a Ratio

1.0000

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

5.9993

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.016520

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

Cs · 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

0.0000

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

39.713%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.7916

smaller = more stable mixing

VEC

3.800

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

0.000

kJ/mol; negative = exothermic mixing

Entropy Norm

0.9602

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.400

Family

Cs-rich Multi-Component

Matrix Element

Cs · 0.400

Related Tasks

Related computation task IDs (5)

aaadnhnv aaadrmby aaaeankz aaaeudyn aaafdbvt

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-8770

Reference Citation

The crystal structure and related material properties of Cs2CoSe2 were obtained from the Materials Project database (MP-ID: mp-8770, 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_Cs2CoSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.80683690
_cell_length_b   8.80683690
_cell_length_c   8.80683690
_cell_angle_alpha   135.66702945
_cell_angle_beta   129.17232484
_cell_angle_gamma   69.69939047
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Cs2CoSe2
_chemical_formula_sum   'Cs4 Co2 Se4'
_cell_volume   363.05978489
_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
  Cs  Cs0  1  0.81897800  0.64584300  0.17313600  1.0
  Cs  Cs1  1  0.18102200  0.35415700  0.82686400  1.0
  Cs  Cs2  1  0.52729300  0.85415700  0.67313600  1.0
  Cs  Cs3  1  0.47270700  0.14584300  0.32686400  1.0
  Co  Co4  1  0.00000000  0.75000000  0.75000000  1.0
  Co  Co5  1  0.00000000  0.25000000  0.25000000  1.0
  Se  Se6  1  0.25523600  0.59129200  0.66394400  1.0
  Se  Se7  1  0.07265200  0.90870800  0.16394400  1.0
  Se  Se8  1  0.92734800  0.09129200  0.83605600  1.0
  Se  Se9  1  0.74476400  0.40870800  0.33605600  1.0

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