material

KFeSe2

ID:

mp-9884

DOI:

10.17188/1316769


Tags: Potassium iron(III) selenide

Material Details

Final Magnetic Moment
2.855 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
-0.654 eV

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

Energy Above Hull / Atom
0.000 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
3.77 g/cm3

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

Decomposes To
Stable
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
C2/c [15]
Hall
-C 2yc
Point Group
2/m
Crystal System
monoclinic

Electronic Structure

Topological data for ICSD ID 40780 from Topological Materials Database
Topological Classification
SM*
Subclassification
ESFD
Crossing Type
Point
* Semimetal
Enforced Semimetal with Fermi point Degeneracy

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]
NdGaO3 (mp-3196) <1 0 0> <1 0 0> 0.001 131.7
MgF2 (mp-1249) <1 0 1> <1 0 0> 0.001 131.7
TeO2 (mp-2125) <0 1 1> <0 1 0> 0.005 76.0
CdWO4 (mp-19387) <0 1 0> <1 0 0> 0.011 131.7
LiGaO2 (mp-5854) <0 1 1> <0 1 0> 0.013 342.1
AlN (mp-661) <1 0 0> <1 0 0> 0.019 329.2
NdGaO3 (mp-3196) <0 0 1> <0 1 0> 0.020 152.0
C (mp-48) <1 0 0> <1 0 -1> 0.020 171.7
CdS (mp-672) <1 0 0> <0 1 0> 0.021 114.0
BaTiO3 (mp-5986) <1 0 1> <1 0 0> 0.022 329.2
C (mp-48) <1 0 1> <1 0 -1> 0.026 257.6
LiAlO2 (mp-3427) <0 0 1> <0 1 0> 0.029 190.1
C (mp-66) <1 1 0> <1 0 0> 0.033 197.5
GaN (mp-804) <1 1 0> <1 0 0> 0.034 263.4
CaF2 (mp-2741) <1 1 1> <0 1 0> 0.036 266.1
BaTiO3 (mp-5986) <1 1 0> <1 0 0> 0.036 263.4
GaN (mp-804) <0 0 1> <0 1 0> 0.038 190.1
Ga2O3 (mp-886) <1 0 0> <1 0 -1> 0.043 257.6
Au (mp-81) <1 1 0> <1 0 0> 0.047 197.5
LiAlO2 (mp-3427) <1 0 0> <0 1 0> 0.047 228.1
ZrO2 (mp-2858) <0 0 1> <0 1 0> 0.049 190.1
LiTaO3 (mp-3666) <0 0 1> <1 1 0> 0.052 304.1
SrTiO3 (mp-4651) <1 0 0> <1 0 0> 0.052 131.7
MgF2 (mp-1249) <1 1 0> <1 1 -1> 0.053 187.8
BN (mp-984) <0 0 1> <0 1 0> 0.054 342.1
MgF2 (mp-1249) <1 0 0> <0 1 0> 0.055 266.1
GaP (mp-2490) <1 1 1> <0 1 0> 0.057 266.1
Al2O3 (mp-1143) <0 0 1> <0 1 0> 0.058 342.1
NdGaO3 (mp-3196) <1 0 1> <1 0 0> 0.060 263.4
InP (mp-20351) <1 1 0> <1 0 0> 0.061 197.5
LiGaO2 (mp-5854) <1 0 0> <1 1 -1> 0.063 281.7
Ni (mp-23) <1 0 0> <0 1 0> 0.063 304.1
SiO2 (mp-6930) <1 0 1> <1 1 -1> 0.064 281.7
NaCl (mp-22862) <1 1 0> <0 1 0> 0.068 228.1
Cu (mp-30) <1 1 0> <1 0 -1> 0.070 257.6
GaN (mp-804) <1 1 1> <0 1 0> 0.070 342.1
Ag (mp-124) <1 1 0> <1 0 0> 0.071 197.5
DyScO3 (mp-31120) <0 0 1> <1 0 1> 0.071 126.6
SrTiO3 (mp-4651) <1 0 1> <1 0 0> 0.076 329.2
BN (mp-984) <1 0 1> <1 1 -1> 0.076 281.7
ZrO2 (mp-2858) <1 1 1> <1 0 -1> 0.076 257.6
CdTe (mp-406) <1 0 0> <0 1 0> 0.077 266.1
InSb (mp-20012) <1 0 0> <0 1 0> 0.079 266.1
LiNbO3 (mp-3731) <0 0 1> <1 1 0> 0.082 304.1
BaTiO3 (mp-5986) <0 0 1> <0 1 0> 0.082 114.0
Au (mp-81) <1 0 0> <0 1 0> 0.089 266.1
ZrO2 (mp-2858) <0 1 0> <1 1 -1> 0.091 281.7
Cu (mp-30) <1 0 0> <0 1 0> 0.094 266.1
ZnO (mp-2133) <1 1 0> <0 1 0> 0.095 152.0
TeO2 (mp-2125) <0 0 1> <1 0 0> 0.096 65.8
Up to 50 entries displayed.
minimal coincident interface area.

Elasticity

Reference for tensor and properties:
Stiffness Tensor Cij (GPa)
20 12 13 0 -0 0
12 25 10 0 -2 0
13 10 55 0 0 0
0 0 0 3 0 -1
-0 -2 0 0 13 0
0 0 0 -1 0 7
Compliance Tensor Sij (10-12Pa-1)
77.3 -31.4 -12.8 0 -2.3 0
-31.4 56 -3.1 0 8.2 0
-12.8 -3.1 21.9 0 -1.1 0
0 0 0 293.2 0 23.9
-2.3 8.2 -1.1 0 80.9 0
0 0 0 23.9 0 151
Shear Modulus GV
9 GPa
Bulk Modulus KV
19 GPa
Shear Modulus GR
6 GPa
Bulk Modulus KR
16 GPa
Shear Modulus GVRH
8 GPa
Bulk Modulus KVRH
18 GPa
Elastic Anisotropy
2.20
Poisson's Ratio
0.31

Similar Structures beta feature

Explanation of dissimilarity measure: Documentation.
material dissimilarity Ehull # of elements
KFeS2 (mp-3827) 0.1793 0.018 3
RbVSe2 (mp-12024) 0.3007 0.000 3
RbFeSe2 (mp-7086) 0.1567 0.026 3
RbFeSe2 (mp-917532) 0.1767 0.026 3
RbFeS2 (mp-1080808) 0.2792 0.000 3
K2NbCuSe4 (mp-9003) 0.1929 0.000 4
K2TaCuSe4 (mp-8972) 0.1962 0.000 4
K2NbCuS4 (mp-9763) 0.1264 0.000 4
Rb2TaCuS4 (mp-11923) 0.2024 0.000 4
Rb2NbCuS4 (mp-15221) 0.2022 0.000 4
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 Fe_pv Se
Final Energy/Atom
-4.7964 eV
Corrected Energy
-38.3714 eV
-38.3714 eV = -38.3714 eV (uncorrected energy)

Detailed input parameters and outputs for all calculations


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ICSD IDs
  • 40780
Submitted by
User remarks:
  • Potassium iron(III) selenide

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)