material

K2MgH4

ID:

mp-23956

DOI:

10.17188/1199829


Tags: High pressure experimental phase Dipotassium magnesium hydride

Material Details

Final Magnetic Moment
-0.000 μB

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

Magnetic Ordering
Non-magnetic
Formation Energy / Atom
-0.333 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
1.58 g/cm3

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

Decomposes To
Stable
Band Gap
3.439 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 ↑ ↓

Vibrational Properties

Reference for phonon calculations and visualization: Visualize with phononwebsite

Phonon dispersion

Density of States
Warning! These calculations were performed using a PBEsol exchange correlation functional in the framework of DFPT using the Abinit code. 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]
Ge(Bi3O5)4 (mp-23352) <1 0 0> <0 0 1> 0.000 212.1
Al (mp-134) <1 0 0> <0 0 1> 0.000 16.3
TiO2 (mp-390) <0 0 1> <0 0 1> 0.000 130.5
Cu (mp-30) <1 0 0> <0 0 1> 0.001 65.3
KCl (mp-23193) <1 0 0> <0 0 1> 0.001 81.6
KTaO3 (mp-3614) <1 1 1> <0 0 1> 0.001 310.0
Al (mp-134) <1 1 1> <0 0 1> 0.002 310.0
KTaO3 (mp-3614) <1 0 0> <0 0 1> 0.003 16.3
AlN (mp-661) <1 0 1> <0 0 1> 0.005 195.8
Ni (mp-23) <1 1 0> <1 0 1> 0.006 172.9
NaCl (mp-22862) <1 0 0> <0 0 1> 0.008 32.6
BN (mp-984) <1 0 1> <1 0 0> 0.008 221.1
Fe3O4 (mp-19306) <1 0 0> <0 0 1> 0.010 146.8
ZnO (mp-2133) <0 0 1> <0 0 1> 0.011 179.5
DyScO3 (mp-31120) <0 0 1> <1 1 0> 0.011 156.3
DyScO3 (mp-31120) <1 0 0> <0 0 1> 0.011 228.4
KTaO3 (mp-3614) <1 1 0> <0 0 1> 0.014 114.2
NaCl (mp-22862) <1 1 0> <0 0 1> 0.015 228.4
YAlO3 (mp-3792) <1 1 0> <0 0 1> 0.016 277.3
ZnSe (mp-1190) <1 0 0> <0 0 1> 0.017 32.6
Ni (mp-23) <1 1 1> <0 0 1> 0.017 342.6
Al2O3 (mp-1143) <1 0 1> <1 0 0> 0.018 331.7
YAlO3 (mp-3792) <0 1 0> <0 0 1> 0.022 310.0
TbScO3 (mp-31119) <0 0 1> <1 1 0> 0.023 156.3
TbScO3 (mp-31119) <1 0 0> <0 0 1> 0.023 228.4
CdWO4 (mp-19387) <0 0 1> <0 0 1> 0.024 244.7
CdS (mp-672) <1 0 1> <1 0 1> 0.024 230.5
Al (mp-134) <1 1 0> <0 0 1> 0.024 114.2
MgO (mp-1265) <1 0 0> <0 0 1> 0.025 146.8
GaAs (mp-2534) <1 0 0> <0 0 1> 0.027 32.6
Mg (mp-153) <1 0 1> <0 0 1> 0.029 375.2
C (mp-48) <1 1 0> <1 0 1> 0.030 230.5
YVO4 (mp-19133) <0 0 1> <0 0 1> 0.032 212.1
YAlO3 (mp-3792) <1 1 1> <0 0 1> 0.033 310.0
InSb (mp-20012) <1 1 1> <1 0 1> 0.035 230.5
TeO2 (mp-2125) <1 0 1> <1 1 0> 0.035 78.2
Ga2O3 (mp-886) <1 0 1> <0 0 1> 0.035 326.3
C (mp-48) <1 0 0> <0 0 1> 0.036 310.0
CdTe (mp-406) <1 1 1> <1 0 1> 0.037 230.5
LaAlO3 (mp-2920) <0 0 1> <1 0 1> 0.038 230.5
MgAl2O4 (mp-3536) <1 1 0> <1 0 1> 0.040 288.2
Mg (mp-153) <1 0 0> <1 0 0> 0.041 165.8
GdScO3 (mp-5690) <1 1 0> <0 0 1> 0.043 65.3
ZnO (mp-2133) <1 0 1> <1 0 0> 0.043 331.7
TeO2 (mp-2125) <1 1 0> <0 0 1> 0.044 97.9
SiC (mp-8062) <1 1 1> <1 0 1> 0.045 230.5
LaAlO3 (mp-2920) <1 0 1> <1 0 1> 0.046 230.5
MoS2 (mp-1434) <0 0 1> <0 0 1> 0.047 326.3
WS2 (mp-224) <0 0 1> <0 0 1> 0.047 326.3
WS2 (mp-224) <1 0 0> <1 0 1> 0.048 230.5
Up to 50 entries displayed.
minimal coincident interface area.

Elasticity

Reference for tensor and properties:
Stiffness Tensor Cij (GPa)
47 13 12 0 0 0
13 47 12 0 0 0
12 12 38 0 0 0
0 0 0 15 0 0
0 0 0 0 15 0
0 0 0 0 0 26
Compliance Tensor Sij (10-12Pa-1)
24.1 -5.2 -5.9 0 0 0
-5.2 24.1 -5.9 0 0 0
-5.9 -5.9 30 0 0 0
0 0 0 65.3 0 0
0 0 0 0 65.3 0
0 0 0 0 0 37.8
Shear Modulus GV
18 GPa
Bulk Modulus KV
23 GPa
Shear Modulus GR
17 GPa
Bulk Modulus KR
23 GPa
Shear Modulus GVRH
17 GPa
Bulk Modulus KVRH
23 GPa
Elastic Anisotropy
0.27
Poisson's Ratio
0.20

Similar Structures beta feature

Explanation of dissimilarity measure: Documentation.
material dissimilarity Ehull # of elements
Nd2AlNO3 (mp-546679) 0.6853 0.076 4
Eu2AlNO3 (mp-1025206) 0.6072 0.119 4
Rb2Cr(BrCl)2 (mp-1025321) 0.3662 0.000 4
Ce2AlNO3 (mp-1025275) 0.5992 0.099 4
Pr2AlNO3 (mp-1025277) 0.6755 0.071 4
SnF4 (mp-2706) 0.7231 0.000 2
Cs2CaH4 (mp-697133) 0.0734 0.000 3
Cs2CaF4 (mp-15157) 0.0408 0.000 3
Yb(CsH2)2 (mp-1025273) 0.0435 0.029 3
Na4Br2O (mp-28599) 0.0745 0.000 3
K2MgF4 (mp-31212) 0.0601 0.000 3
Sr5La5Cu(NiO5)4 (mp-690554) 0.6784 0.000 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: H Mg_pv K_sv
Final Energy/Atom
-2.7299 eV
Corrected Energy
-19.1090 eV
-19.1090 eV = -19.1090 eV (uncorrected energy)

Detailed input parameters and outputs for all calculations


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ICSD IDs
  • 68358
Submitted by
User remarks:
  • High pressure experimental phase
  • Dipotassium magnesium hydride

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)