JVASP-9564_Mg2Sb2O5
JARVIS-ID:JVASP-9564 Functional:optB88-vdW Primitive cell Primitive cell Conventional cell Conventional cell
Chemical formula:Mg2Sb2O5 Formation energy/atom (eV):-1.995 a 3.136 Å α:89.999 ° a 3.136 Å α:90.0 °
Space-group :Pmc2_1, 26 Relaxed energy/atom (eV):-4.0015 b 9.586 Å β:89.999 ° b 8.391 Å β:90.0 °
Calculation type:Bulk SCF bandgap (eV):0.865 c 8.391 Å γ:90.0 ° c 9.586 Å γ:90.0 °
Crystal system:orthorhombic Point group:mm2 Density (gcm-3):4.9 Volume (3):252.19 nAtoms_prim:18 nAtoms_conv:18
Download input files

Convergence [Reference]

Calculations are done using VASP software [Source-code]. Convergence on KPOINTS [Source-code] and ENCUT [Source-code] 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 (number of ionic steps, NSW=1 ). However, for very accurate calculations, NSW>1 might be needed.


Structural analysis [Reference]

The following shows the X-ray diffraction (XRD)[Source-code] pattern and the Radial distribution function (RDF) plots [Source-code]. XRD peaks should be comparable to experiments for bulk structures. Relative intensities may differ. For mono- and multi-layer structures , we take the z-dimension during DFT calculation for XRD calculations, which may differ from the experimental set-up.


Electronic structure [Reference]

The following shows the electronic density of states and bandstructure [Source-code]. 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. If available, MBJ data should be comparable to experiments also. Total DOS, Orbital DOS and Element dos [Source-code] buttons are provided for density of states options. Energy is rescaled to make Fermi-energy zero. In the bandstructure plot [Source-code], spin up 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): 0.825D


Electrostatic potential [Reference]

The following plot shows the plane averaged electrostatic potential (ionic+Hartree) along x, y and z-directions. The red line shows the Fermi-energy while the green line shows the maximum value of the electrostatic potential. For slab structures (with vacuum along z-direction), the difference in these two values can be used to calculate work-function of the material.


Spin-orbit coupling based spillage [Reference]

Below we show results from spin-orbit coupling (SOC) based spillage calculations using wavefunctions of spin-orbit and non-spin-orbit bandstructure calculations. a) non-SOC band structure and b) SOC band structure, c) non-SOC projected band structure and d) SOC projected band structure, projecting onto highest energy orbital of most electronegative atom in the system (assuming the orbital forms the valence band-maximum). e) Spillage, as a function of momentum, k. f) Table of bandgaps and spillage information. Generally, spillage values greater than 0.5 and indirect gap close to zero indicate topological materials.

Spin-orbit spillage is: 0.038


Optoelectronic properties Semi-local [Reference]

Incident photon energy dependence of optical is shown below [Source-code]. 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 mono-/multi-layer materials were rescaled with the actual thickness to simulation z-box ratio. Absorption coeffiecient is in cm-1 unit. Also, ionic contributions were neglected.

Dense k-mesh based bandgap is : 0.8648 eV

Static real-parts of dielectric function in x,y,z: 7.79,5.3,4.49


DFPT: IR-intensity, Piezoelecric and Dielectric tensors [Reference]

Calculations are done using density functional perturbation theory (DFPT) method for non-metallic systems for conventional cell and at Gamma-point in phonon BZ.

Static dielecric-tensor

13.66 -0.0 -0.0
-0.0 9.09 0.02
-0.0 0.02 23.74

Piezoelectric-stress-tensor (C/m2)

-0.0 -0.0 -0.0 0.2 0.0 -0.0
0.46 0.24 0.15 0.0 -0.0 0.0
-0.0 -0.0 0.0 0.0 -0.29 0.0

Finite-difference: elastic tensor and derived phonon properties [Reference]

Elastic tensor calculated for the conventional cell of the system with finite-difference method [Source-code]. For bulk structures, elastic constants are given in GPa unit . 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 [Source-code] from this calculation are also shown.

WARNING: Please note we provide finite-size cell phonons only. At least 1.2 nm x1.2 nm x1.2 nm size cell or more is generally needed for obtaining reliable phonon spectrum, but we take conventional cell of the structure only. For systems having primitive-cell phonon representation tables, I denotes infrared activity and R denotes Raman active modes (where applicabale). Selection of particular q-point mesh can give rise to unphysical negative modes in phonon density of states and phonon bandstructre. The minimum thermal conductivity was calculated using elastic tensor information following Clarke and Cahill formalism.

Voigt-bulk modulus (KV): 56.06 GPa, Voigt-shear modulus (GV): 31.47 GPa

Reuss-bulk modulus (KR): 44.71 GPa, Reuss-shear modulus (GR): 22.54 GPa

Poisson's ratio: 0.27, Elastic anisotropy parameter: 2.24

Clarke's lower limit of thermal conductivity (W/(m.K)): 0.77

Cahill's lower limit of thermal conductivity (W/(m.K)): 0.85

Elastic tensor
193.5 22.1 41.4 0.0 -0.0 0.0
22.1 79.1 9.7 0.0 0.0 -0.0
41.4 9.7 85.5 0.0 -0.0 -0.0
0.0 0.0 0.0 11.4 0.0 0.0
-0.0 0.0 -0.0 0.0 32.5 0.0
0.0 -0.0 -0.0 0.0 0.0 18.5

Phonon mode (cm-1)
-0.09
-0.08
-0.01
40.76
64.25
70.72
71.78
76.71
78.74
82.83
92.78
121.13
127.0
138.48
146.81
147.47
152.76
154.01
183.81
203.8
217.35
245.01
248.74
254.58
257.16
269.05
312.19
325.42
342.0
348.61
366.7
381.6
385.76
391.89
396.06
408.77
409.3
412.55
416.16
420.17
426.57
427.51
432.11
444.93
466.05
467.48
493.84
494.83
553.89
575.11
603.17
625.95
703.33
704.04

Point group

point_group_type: m

Visualize Phonons here
Phonon mode (cm-1) Representation
-0.09
-0.0926622701
-0.08
-0.0784001038
-0.01
-0.011578991
40.76
40.7632841485
64.25
64.2506974982
70.72
70.71704719
71.78
71.7772930037
76.71
76.712807895
78.74
78.7397631454
82.83
82.8312819197
92.78
92.775870493
121.13
121.128972819
127.0
127.001224367
138.48
138.476094354
146.81
146.811113509
147.47
147.472959596
152.76
152.764794598
154.01
154.010745236
183.81
183.813476413
203.8
203.801106019
217.35
217.345269573
245.01
245.007657898
248.74
248.744148114
254.58
254.580944661
257.16
257.156862008
269.05
269.047128212
312.19
312.188448632
325.42
325.416387162
342.0
342.001048749
348.61
348.605837459
366.7
366.702983752
381.6
381.60364984
385.76
385.758947341
391.89
391.892815257
396.06
396.063050919
408.77
408.769343247
409.3
409.299557633
412.55
412.554956602
416.16
416.160507326
420.17
420.166314351
426.57
426.566061634
427.51
427.507961634
432.11
432.110654407
444.93
444.927086162
466.05
466.048619725
467.48
467.481462073
493.84
493.842891325
494.83
494.826121514
553.89
553.886719885
575.11
575.108689381
603.17
603.167172499
625.95
625.954265418
703.33
703.333405905
704.04
704.044619624

Magnetic moment [Reference]

The orbital magnetic moment was obtained after SCF run. This is not a DFT+U calculation, hence the data could be used to predict zero or non-zero magnetic moment nature of the material only.

Total magnetic moment: -0.0 μB

Magnetic moment per atom: -0.0 μB

Magnetization
Elementsspdtot
Mg-0.0-0.0-0.0-0.0
Mg-0.00.0-0.0-0.0
Mg0.00.00.00.0
Mg0.00.00.00.0
Sb-0.0-0.0-0.0-0.0
Sb-0.0-0.0-0.0-0.0
Sb0.00.0-0.0-0.0
Sb0.00.00.00.0
O-0.0-0.00.0-0.0
O-0.0-0.00.0-0.0
O0.00.00.00.0
O0.00.00.00.0
O-0.00.00.0-0.0
O0.0-0.00.0-0.0
O0.0-0.00.0-0.0
O-0.00.00.00.0
O-0.00.00.00.0
O-0.00.00.00.0

See also

Links to other databases or papers are provided below


mvc-3865

MP link
mvc-3865

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