material

K(FeAs)2
ID:

mp-675576
DOI:

10.17188/1282758

Tags: High pressure experimental phase Potassium iron arsenide (1/2/2) Potassium iron iron(III) arsenide

Material Details

Final Magnetic Moment
1.480 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
-0.289 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
4.96 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
I4/mmm [139]
Hall
-I 4 2
Point Group
4/mmm
Crystal System
tetragonal

Band Structure

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

sign indicates spin ↑ ↓

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:
No elastic tensor calculated for this material, so elastic energies not avaialable. Sorting by MCIA instead.
substrate material substrate orientation film orientation MCIA† [Å2]
LaAlO3 (mp-2920) <0 0 1> <1 1 1> 75.6
LaAlO3 (mp-2920) <1 0 1> <1 1 1> 75.6
AlN (mp-661) <0 0 1> <0 0 1> 42.5
AlN (mp-661) <1 0 0> <0 0 1> 156.0
AlN (mp-661) <1 0 1> <0 0 1> 198.6
AlN (mp-661) <1 1 0> <1 1 0> 297.0
AlN (mp-661) <1 1 1> <1 1 0> 222.8
CeO2 (mp-20194) <1 0 0> <0 0 1> 28.4
CeO2 (mp-20194) <1 1 0> <1 0 0> 210.0
CeO2 (mp-20194) <1 1 1> <0 0 1> 255.3
BaF2 (mp-1029) <1 0 0> <0 0 1> 354.6
GaN (mp-804) <1 0 0> <0 0 1> 85.1
GaN (mp-804) <1 0 1> <0 0 1> 212.7
GaN (mp-804) <1 1 0> <1 1 0> 148.5
GaN (mp-804) <1 1 1> <0 0 1> 127.6
SiO2 (mp-6930) <1 0 0> <1 0 0> 315.0
SiO2 (mp-6930) <1 0 1> <0 0 1> 312.0
KCl (mp-23193) <1 1 0> <0 0 1> 297.8
DyScO3 (mp-31120) <0 0 1> <1 1 1> 151.2
DyScO3 (mp-31120) <0 1 0> <1 1 0> 297.0
DyScO3 (mp-31120) <0 1 1> <0 0 1> 255.3
DyScO3 (mp-31120) <1 1 0> <0 0 1> 127.6
DyScO3 (mp-31120) <1 1 1> <0 0 1> 269.5
InAs (mp-20305) <1 1 1> <0 0 1> 340.4
KTaO3 (mp-3614) <1 0 0> <0 0 1> 127.6
KTaO3 (mp-3614) <1 1 1> <0 0 1> 382.9
CdS (mp-672) <1 0 0> <0 0 1> 354.6
CdS (mp-672) <1 0 1> <1 0 1> 217.5
LiF (mp-1138) <1 0 0> <0 0 1> 127.6
LiF (mp-1138) <1 1 0> <1 0 0> 262.5
Te2W (mp-22693) <1 0 0> <0 0 1> 283.7
YVO4 (mp-19133) <1 0 1> <1 0 1> 271.9
GaAs (mp-2534) <1 0 0> <0 0 1> 127.6
GaAs (mp-2534) <1 1 1> <1 1 0> 222.8
TePb (mp-19717) <1 0 0> <1 0 1> 217.5
TePb (mp-19717) <1 1 0> <0 0 1> 297.8
GaN (mp-804) <0 0 1> <0 0 1> 156.0
Te2Mo (mp-602) <0 0 1> <0 0 1> 226.9
Te2Mo (mp-602) <1 1 0> <0 0 1> 283.7
Ag (mp-124) <1 0 0> <0 0 1> 70.9
GaSe (mp-1943) <0 0 1> <0 0 1> 99.3
BN (mp-984) <0 0 1> <0 0 1> 113.5
BN (mp-984) <1 0 1> <0 0 1> 241.1
LiNbO3 (mp-3731) <0 0 1> <0 0 1> 70.9
LiNbO3 (mp-3731) <1 0 0> <1 1 0> 74.3
DyScO3 (mp-31120) <1 0 1> <0 0 1> 212.7
InAs (mp-20305) <1 0 0> <0 0 1> 184.4
ZnSe (mp-1190) <1 0 0> <0 0 1> 127.6
ZnSe (mp-1190) <1 1 1> <1 1 0> 222.8
KTaO3 (mp-3614) <1 1 0> <1 1 1> 302.4
Up to 50 entries displayed.
†minimal coincident interface area.

Elasticity

Reference for tensor and properties:
Visualize with ELATE
Stiffness Tensor Cij (GPa)
85 41 35 0 0 0
41 85 35 0 0 0
35 35 56 0 0 0
0 0 0 23 0 0
0 0 0 0 23 0
0 0 0 0 0 36
Compliance Tensor Sij (10-12Pa-1)
17.2 -5 -7.6 0 0 0
-5 17.2 -7.6 0 0 0
-7.6 -7.6 27.4 0 0 0
0 0 0 42.7 0 0
0 0 0 0 42.7 0
0 0 0 0 0 27.5
Shear Modulus GV
24 GPa
Bulk Modulus KV
50 GPa
Shear Modulus GR
22 GPa
Bulk Modulus KR
47 GPa
Shear Modulus GVRH
23 GPa
Bulk Modulus KVRH
48 GPa
Elastic Anisotropy
0.49
Poisson's Ratio
0.29

Similar Structures beta feature

Explanation of dissimilarity measure: Documentation.
material dissimilarity Ehull # of elements
Rb(FeAs)2 (mp-975359) 0.1862 0.000 3
K(CoAs)2 (mp-569408) 0.2471 0.000 3
Rb(CoSe)2 (mp-570091) 0.2948 0.022 3
Cs(AsRh)2 (mp-569012) 0.1814 0.000 3
Cs(CoSe)2 (mp-571343) 0.2686 0.024 3
U2Cu2As3O (mp-572929) 0.6755 0.000 4
Sm2CuAs3O (mp-1005792) 0.6733 0.000 4
SrAgSF (mp-1078562) 0.6726 0.005 4
ThAgPO (mp-1079993) 0.6317 0.011 4
SrAgTeF (mp-1080438) 0.6931 0.000 4
Bi3O2 (mp-1022722) 0.2855 0.127 2
Ce8Fe8As8O7F (mp-705511) 0.7066 0.113 5
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 As
Final Energy/Atom
-5.7572 eV
Corrected Energy
-28.7859 eV
-28.7859 eV = -28.7859 eV (uncorrected energy)

Detailed input parameters and outputs for all calculations

Show JSON History Show BibTex Citation Download BibTex Citation
ICSD IDs
  • 189036
  • 31473
Submitted by
User remarks:
  • High pressure experimental phase
  • Potassium iron arsenide (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)