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Structural formula: Mg2 Sn1 W1 O6

Functional: optB88-vDW

Space group : P1

Calculation type: Bulk

JARVIS ID: JVASP-9888

Formation energy/atom (eV): -2.309

Relaxed energy/atom (eV): -5.057

Primitive cell lattice parameters

a 5.175 Å , b 5.64 Å , c 5.651 Å

α 72.645 ° , β 66.259 ° , γ 67.366 °

Conventional cell lattice parameters

a 5.175 Å , b 5.64 Å , c 5.651 Å

α 72.645 ° , β 66.259 ° , γ 67.366 °

Download input files

Convergence

Calculations are done using VASP software. Convergence on KPOINTS and ENCUT is done with respect to total energy of the system within 0.001 eV tolerance. Please note convergence on KPOINTS and ENCUT is generally done for target properties, but here we assume energy-convergence with 0.001 eV should be sufficient for other properties also. The points on the curves are obtained with single-point calculation (nuber of ionic steps,NSW=1). However, for very accurate calculations, NSW>1 might be needed.

Structural analysis

The following shows the X-ray diffraction (XRD) pattern and the Radial distribution function (RDF) plots. XRD peaks should be comparable to experiments for bulk structures. Relative intensities may differ.

Optical properties Semi-local

Incident photon energy dependence of optical is shown below. Only interband optical transitions are taken into account.Please note the underestimatation of band-gap problem with DFT will reflect in the spectra as well. For very accurate optical properties GW/BSE calculation would be needed, which is yet to be done because of their very high computational cost. Optical properties for layered materials needs to be rescaled with the actual thickness to simulation z-box ratio. Absorption coeffiecient is in cm-1 unit.

Dense k-mesh based bandgap is : 1.815 eV

Optical properties METAGGA-MBJ

Single point DFT calculation was carried out with meta-gga MBJ functional. This should give reasonable bandgap, and optical properties assuming the calculation was properly converged. Incident photon energy dependence of optical is shown below. Only interband optical transitions are taken into account.

MBJ bandgap is : 2.5508 eV

Elastic tensor and derived phonon properties

Elastic tensor calculated for the conventional cell of the system with finite-difference method. For layered materials, the elastic constants are rescaled with respect to vacuum padding (see the input files) and the units for elastic coefficients are in N/m. Phonons obtained from this calcuation are also shown.

WARNING: Please note this may not be the exact phonon modes of the system as we did not test the cell-size dependence of phonons yet. At least 1.2 nm x1.2 nm x1.2 nm or more is needed for obtaining reliable phonon spectrum. For systems having primitive-cell phonon representation tables, I denotes infrared activity and R denotes Raman active modes (where applicabale). The minimum thermal conductivity was calculated using elastic tensor information following Clarke and Cahill formalism.

Bulk Modulus BV 93.656 GPa

Shear Modulus GV 36.893 GPa

161.6 74.2 72.5 -1.7 -9.0 3.8
74.2 158.7 56.7 6.0 2.7 -5.7
72.5 56.7 115.8 -1.6 5.4 16.3
-1.7 6.0 -1.6 38.7 -11.1 8.7
-9.0 2.7 5.4 -11.1 39.4 -9.7
3.8 -5.7 16.3 8.7 -9.7 28.8
Phonon mode (cm-1)
-46.4205342483
-0.0644359723
-0.0511587137
-0.0399788522
77.8063307885
131.139118852
140.858366952
172.025219332
176.876931174
194.266681135
227.803475279
243.121203747
259.664325382
276.377249994
326.872070838
347.045968989
352.143898496
371.605209457
381.72440075
398.356952819
423.549754364
445.12018862
478.951806421
506.292765504
527.448183575
581.693378003
592.904336623
653.813133504
770.487619155
884.006327877

Point group

point_group_type: 1

Visualize Phonons here
Phonon mode (cm-1) Representation
-46.4205342484 A I+R
-0.0644359723 A I+R
-0.0511587138 A I+R
-0.0399788525 A I+R
77.8063307885 A I+R
131.139118852 A I+R
140.858366952 A I+R
172.025219332 A I+R
176.876931174 A I+R
194.266681135 A I+R
227.803475279 A I+R
243.121203747 A I+R
259.664325382 A I+R
276.377249994 A I+R
326.872070838 A I+R
347.045968989 A I+R
352.143898496 A I+R
371.605209457 A I+R
381.72440075 A I+R
398.356952819 A I+R
423.549754364 A I+R
445.12018862 A I+R
478.951806421 A I+R
506.292765504 A I+R
527.448183575 A I+R
581.693378003 A I+R
592.904336623 A I+R
653.813133504 A I+R
770.487619155 A I+R
884.006327877 A I+R

Magnetic moment

The orbital magnetic moment was obtained after SCF run. Please note no DFT+U parameters were taken into account.

1.121 μB

Reference


mvc-5921
mvc-5921 MP link