Basic Information
Formula
Cs2CoSe2
MP-ID
mp-8770
Elements
3
Sites
10
Density
4.4152
g/cm³
Volume
363.06
ų
Cell a
8.8068
Å
Cell b
8.8068
Å
Cell c
8.8068
Å
α Angle
135.67
°
β Angle
129.17
°
γ Angle
69.70
°
Space Group
Ibam
Point Group
mmm
Crystal System
Orthorhombic
Bravais Lattice
oI
Stability
No
Packing Fraction
-
X-ray Diffraction
Diffraction Pattern
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) |
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
ų
c/a Ratio
1.0000
Electronic Properties
Metallic
Metal
Band Gap
0
eV
Direct Gap
No
CBM
N/A
eV
Magnetic Properties
Magnetic
Yes
Total Mag. Moment
5.9993
μB
Mag. Ordering
FM
Mag. Sites
2
Magnetization/Volume
0.016520
μB/ų
Elastic Properties
Elastic data not available
Feature Analysis
Element Composition (atomic fraction)
Composition Info
Major / Matrix Element
Cs · 0.400
Element Family
Alkali-AlkEarth
Solute Fraction
0.600
Interstitial Fraction
0.000
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
0
Phase Tendency
IM
Related Tasks
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
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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
