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Structural formula: Sn1 W2 O8

Functional: optB88-vDW

Space group : P-1

Calculation type: Bulk

JARVIS ID: JVASP-9334

Formation energy/atom (eV): -1.949

Relaxed energy/atom (eV): -6.1403

Primitive cell lattice parameters

a 5.017 Å , b 5.41 Å , c 6.4 Å

α 109.6 ° , β 92.161 ° , γ 105.622 °

Conventional cell lattice parameters

a 5.017 Å , b 5.41 Å , c 6.4 Å

α 109.6 ° , β 92.161 ° , γ 105.622 °

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.

Electronic structure

The following shows the electronic density of states and bandstructure. DFT is generally predicted to underestimate bandgap of materials. Accurate band-gaps are obtained with higher level methods (with high computational requirement) such as HSE, GW, which are under progress. Total DOS, Orbital DOS and Element dos buttons are provided for density of states options. Energy is rescaled to make Fermi-energy zero. In the bandstructure plot, spin up is is shown with blue lines while spin down are shown with red lines. Non-degenerate spin-up and spin-down states (if applicable) would imply a net orbital magnetic moment in the system. Fermi-occupation tolerance for bandgap calculation is chosen as 0.001.

High-symmetry kpoints based bandgap (eV): 1.5394I

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 : 1.5169 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 38.333 GPa

Shear Modulus GV 25.74 GPa

60.9 38.2 -1.3 4.1 -2.3 18.2
38.2 167.9 10.6 18.8 -1.7 9.5
-1.3 10.6 21.2 -3.6 4.4 13.1
4.1 18.8 -3.6 53.9 0.1 0.2
-2.3 -1.7 4.4 0.1 0.1 7.3
18.2 9.5 13.1 0.2 7.3 7.2
Phonon mode (cm-1)
-74.3813669684
-0.1105244211
-0.0713419159
0.1072287628
49.83807618
65.1819146731
74.7133810172
133.085337265
161.707111314
164.312683036
170.310678862
176.973773326
190.395037336
220.239147435
262.067070746
274.685568239
281.241119654
306.760387573
361.144434612
422.972895893
423.859051015
481.081731743
485.812980643
535.181124449
552.43102043
706.033906605
741.127106871
774.053706324
799.290686249
922.872020111
923.990852736
1133.47550091
1146.1096202

Point group

point_group_type: -1

Visualize Phonons here
Phonon mode (cm-1) Representation
-74.3813669684 Au I
-0.1105244203 Au I
-0.0713419159 Au I
0.1072287635 Au I
49.83807618 Ag R
65.1819146731 Au I
74.7133810172 Ag R
133.085337265 Ag R
161.707111314 Au I
164.312683036 Ag R
170.310678862 Ag R
176.973773326 Au I
190.395037336 Au I
220.239147435 Ag R
262.067070746 Au I
274.685568239 Ag R
281.241119654 Au I
306.760387573 Au I
361.144434612 Ag R
422.972895893 Ag R
423.859051015 Au I
481.081731743 Ag R
485.812980643 Au I
535.181124449 Au I
552.43102043 Ag R
706.033906605 Au I
741.127106871 Ag R
774.053706324 Ag R
799.290686249 Au I
922.872020111 Au I
923.990852736 Ag R
1133.47550091 Au I
1146.1096202 Ag R

Magnetic moment

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

0.000 μB

Reference


mvc-668
mvc-668 MP link