material

K(CoSe)2

ID:

mp-4668

DOI:

10.17188/1208327


Tags: cobalt potassium selenide (2/1/2) Potassium cobalt selenide (1/2/2) - ferromagnetic Potassium cobalt selenide (1/2/2) Potassium cobalt selenide (1/2/2) - non magnetic

Material Details

Final Magnetic Moment
2.241 μB

Calculated total magnetic moment for the unit cell within the magnetic ordering provided (see below). Typically accurate to the second digit.

Magnetic Ordering
FM
Formation Energy / Atom
-0.478 eV

Calculated formation energy from the elements normalized to per atom in the unit cell.

Energy Above Hull / Atom
0.026 eV

The energy of decomposition of this material into the set of most stable materials at this chemical composition, in eV/atom. Stability is tested against all potential chemical combinations that result in the material's composition. For example, a Co2O3 structure would be tested for decomposition against other Co2O3 structures, against Co and O2 mixtures, and against CoO and O2 mixtures.

Density
5.16 g/cm3

The calculated bulk crystalline density, typically underestimated due calculated cell volumes overestimated on average by 3% (+/- 6%)

Decomposes To
Co9Se8 + K2Se + Co
Band Gap
0.000 eV

In general, band gaps computed with common exchange-correlation functionals such as the LDA and GGA are severely underestimated. Typically the disagreement is reported to be ~50% in the literature. Some internal testing by the Materials Project supports these statements; typically, we find that band gaps are underestimated by ~40%. We additionally find that several known insulators are predicted to be metallic.

Space Group

Hermann Mauguin
I4/mmm [139]
Hall
-I 4 2
Point Group
4/mmm
Crystal System
tetragonal

Electronic Structure

Band Structure and Density of States

Warning! Semi-local DFT tends to severely underestimate bandgaps. Please see the wiki for more info.

X-Ray Diffraction

    Select radiation source:
  • Cu
  • Ag
  • Mo
  • Fe

Calculated powder diffraction pattern; note that peak spacings may be affected due to inaccuracies in calculated cell volume, which is typically overestimated on average by 3% (+/- 6%)

X-Ray Absorption Spectra

FEFF XANES

Select an element to display a spectrum averaged over all sites of that element in the structure.

Apply Gaussian smoothing:

0 eV
3 eV
FWHM: 0 eV

Download spectra for every symmetrically equivalent absorption site in the structure.

Download FEFF Input parameters.

Warning: These results are intended to be semi-quantitative in that corrections, such as edge shifts and Debye-Waller damping, have not been included.

Substrates

Reference for minimal coincident interface area (MCIA) and elastic energy:
substrate orientation:
substrate material substrate orientation film orientation elastic energy [meV] MCIA [Å2]
LiAlO2 (mp-3427) <0 0 1> <0 0 1> 0.000 136.7
CaF2 (mp-2741) <1 0 0> <0 0 1> 0.001 30.4
GaP (mp-2490) <1 0 0> <0 0 1> 0.002 30.4
Mg (mp-153) <0 0 1> <0 0 1> 0.003 167.1
MoS2 (mp-1434) <0 0 1> <0 0 1> 0.004 167.1
WS2 (mp-224) <0 0 1> <0 0 1> 0.004 167.1
MgF2 (mp-1249) <0 0 1> <0 0 1> 0.006 197.5
LiTaO3 (mp-3666) <1 0 0> <1 0 1> 0.007 216.7
Au (mp-81) <1 1 0> <1 0 1> 0.010 270.8
InAs (mp-20305) <1 0 0> <0 0 1> 0.014 76.0
Te2Mo (mp-602) <0 0 1> <1 0 0> 0.019 208.0
ZnTe (mp-2176) <1 0 0> <0 0 1> 0.019 76.0
NdGaO3 (mp-3196) <1 1 0> <0 0 1> 0.022 60.8
C (mp-66) <1 1 0> <0 0 1> 0.023 379.8
GdScO3 (mp-5690) <1 1 1> <0 0 1> 0.024 288.6
Al2O3 (mp-1143) <0 0 1> <0 0 1> 0.026 319.0
Ag (mp-124) <1 1 1> <1 0 0> 0.029 208.0
TbScO3 (mp-31119) <0 0 1> <1 1 0> 0.030 220.6
GdScO3 (mp-5690) <0 1 1> <1 1 0> 0.032 220.6
ZrO2 (mp-2858) <0 0 1> <0 0 1> 0.036 136.7
SiC (mp-8062) <1 0 0> <0 0 1> 0.038 76.0
GaP (mp-2490) <1 1 0> <0 0 1> 0.047 212.7
GdScO3 (mp-5690) <0 0 1> <1 1 0> 0.047 220.6
MgF2 (mp-1249) <1 1 1> <1 1 1> 0.049 150.2
TiO2 (mp-2657) <1 0 0> <0 0 1> 0.051 167.1
SrTiO3 (mp-4651) <1 1 1> <1 0 0> 0.054 208.0
CaCO3 (mp-3953) <1 1 0> <0 0 1> 0.055 151.9
Au (mp-81) <1 1 1> <1 0 0> 0.056 208.0
DyScO3 (mp-31120) <0 0 1> <1 1 0> 0.056 220.6
Ni (mp-23) <1 0 0> <0 0 1> 0.059 60.8
Ag (mp-124) <1 0 0> <0 0 1> 0.062 136.7
GdScO3 (mp-5690) <1 0 1> <0 0 1> 0.066 227.9
YAlO3 (mp-3792) <0 1 1> <0 0 1> 0.069 288.6
TiO2 (mp-2657) <0 0 1> <0 0 1> 0.072 197.5
Al2O3 (mp-1143) <1 1 0> <1 1 0> 0.072 220.6
LiTaO3 (mp-3666) <0 0 1> <1 0 0> 0.072 208.0
Mg (mp-153) <1 1 0> <1 1 0> 0.073 147.1
CaF2 (mp-2741) <1 1 0> <0 0 1> 0.073 212.7
Fe2O3 (mp-24972) <0 0 1> <1 0 0> 0.076 208.0
LiF (mp-1138) <1 1 0> <0 0 1> 0.078 258.3
Bi2Te3 (mp-34202) <0 0 1> <0 0 1> 0.081 121.5
TePb (mp-19717) <1 0 0> <1 0 0> 0.089 260.0
LiGaO2 (mp-5854) <0 0 1> <1 1 0> 0.091 220.6
Si (mp-149) <1 0 0> <0 0 1> 0.092 30.4
C (mp-48) <1 0 0> <1 0 0> 0.092 208.0
ZrO2 (mp-2858) <0 1 1> <0 0 1> 0.096 319.0
CeO2 (mp-20194) <1 0 0> <0 0 1> 0.097 30.4
NaCl (mp-22862) <1 1 0> <1 0 1> 0.098 270.8
Fe2O3 (mp-24972) <1 0 0> <1 0 1> 0.098 216.7
NdGaO3 (mp-3196) <1 1 1> <1 0 0> 0.098 208.0
Up to 50 entries displayed.
minimal coincident interface area.

Elasticity

Reference for tensor and properties:
Stiffness Tensor Cij (GPa)
95 23 24 0 0 0
23 95 24 0 0 0
24 24 45 0 0 0
0 0 0 19 0 0
0 0 0 0 19 0
0 0 0 0 0 34
Compliance Tensor Sij (10-12Pa-1)
12.3 -1.5 -5.7 0 0 0
-1.5 12.3 -5.7 0 0 0
-5.7 -5.7 28.1 0 0 0
0 0 0 52.4 0 0
0 0 0 0 52.4 0
0 0 0 0 0 29.6
Shear Modulus GV
25 GPa
Bulk Modulus KV
42 GPa
Shear Modulus GR
23 GPa
Bulk Modulus KR
37 GPa
Shear Modulus GVRH
24 GPa
Bulk Modulus KVRH
40 GPa
Elastic Anisotropy
0.76
Poisson's Ratio
0.25

Similar Structures beta feature

Explanation of dissimilarity measure: Documentation.
material dissimilarity Ehull # of elements
K(CoSe)2 (mp-4668) 0.0081 0.026 3
K(PRh)2 (mp-12098) 0.1260 0.000 3
Tl(NiSe)2 (mp-4354) 0.0587 0.022 3
Ba(MnP)2 (mp-19857) 0.0968 0.003 3
K(NiSe)2 (mp-1070216) 0.0887 0.051 3
KLiZnS2 (mp-774907) 0.1732 0.000 4
SrBiClO2 (mp-547244) 0.6193 0.000 4
SrBiBrO2 (mp-552234) 0.6284 0.000 4
KLiMnS2 (mp-753940) 0.2676 0.000 4
BiPbClO2 (mp-23084) 0.4737 0.000 4
Bi3O2 (mp-1022722) 0.5091 0.125 2
Up to 5 similar elemental, binary, ternary, quaternary, etc. structures displayed (dissimilarity threshold 0.75). Ehull: energy above hull per atom [eV].

Calculation Summary

Elasticity

Methodology

Structure Optimization

Run Type
GGA
Energy Cutoff
520 eV
# of K-points
None
U Values
--
Pseudopotentials
VASP PAW: K_sv Co Se
Final Energy/Atom
-4.9418 eV
Corrected Energy
-24.7092 eV
-24.7092 eV = -24.7092 eV (uncorrected energy)

Detailed input parameters and outputs for all calculations


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ICSD IDs
  • 67370
  • 182837
  • 182838
  • 623961
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User remarks:
  • Potassium cobalt selenide (1/2/2)

Displaying lattice parameters for primitive cell; note that calculated cell volumes are typically overestimated on average by 3% (+/- 6%). Note the primitive cell may appear less symmetric than the conventional cell representation (see "Structure Type" selector below the 3d structure)