JVASP-11187_Rb2LiAsO4
JARVIS-ID:JVASP-11187 Functional:optB88-vdW Primitive cell Primitive cell Conventional cell Conventional cell
Chemical formula:Rb2LiAsO4 Formation energy/atom (eV):-1.918 a 5.832 Å α:90.0 ° a 5.832 Å α:90.0 °
Space-group :Cmc2_1, 36 Relaxed energy/atom (eV):-3.7114 b 6.547 Å β:90.0 ° b 11.724 Å β:90.0 °
Calculation type:Bulk SCF bandgap (eV):3.905 c 7.91 Å γ:116.448 ° c 7.91 Å γ:90.0 °
Crystal system:orthorhombic Point group:mm2 Density (gcm-3):3.89 Volume (3):270.44 nAtoms_prim:16 nAtoms_conv:32
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): 3.901I


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.


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 : 3.9049 eV

Static real-parts of dielectric function in x,y,z: 2.93,2.96,2.94


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

7.18 0.0 0.0
0.0 7.19 0.0
0.0 0.0 7.0

Piezoelectric-stress-tensor (C/m2)

0.0 -0.0 0.0 0.0 0.0 -0.08
0.0 0.0 0.0 0.0 -0.08 0.0
-0.03 -0.03 0.03 0.0 0.0 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): 40.72 GPa, Voigt-shear modulus (GV): 16.17 GPa

Reuss-bulk modulus (KR): 39.67 GPa, Reuss-shear modulus (GR): 12.48 GPa

Poisson's ratio: 0.34, Elastic anisotropy parameter: 1.51

Clarke's lower limit of thermal conductivity (W/(m.K)): 0.57

Cahill's lower limit of thermal conductivity (W/(m.K)): 0.65

Elastic tensor
90.7 22.0 20.0 -0.0 -0.0 -0.0
22.0 56.0 28.6 0.0 -0.0 -0.0
20.0 28.6 78.6 0.0 -0.0 0.0
0.0 0.0 0.0 8.6 -0.0 0.0
-0.0 0.0 -0.0 -0.0 12.0 -0.0
-0.0 0.0 0.0 0.0 -0.0 8.7

Phonon mode (cm-1)
-0.05
-0.04
-0.03
50.01
63.42
63.56
74.02
77.8
89.02
89.36
90.98
93.34
94.87
100.44
101.79
103.03
112.0
117.08
126.06
132.45
146.56
150.49
172.96
197.46
277.35
289.46
312.09
317.32
339.54
342.91
347.29
353.75
363.07
392.21
394.74
409.94
486.26
505.33
509.18
523.04
742.52
748.53
755.58
768.48
779.68
781.45
795.19
824.86

Point group

point_group_type: mm2

Visualize Phonons here
Phonon mode (cm-1) Representation
-0.05
-0.0509077114
-0.04
-0.0449768678
-0.03
-0.0307001237
50.01
50.0098659392
63.42
63.4189458761
63.56
63.5645318704
74.02
74.0219886794
77.8
77.7969265623
89.02
89.0157484068
89.36
89.3622302006
90.98
90.9779386354
93.34
93.3432882558
94.87
94.8660792309
100.44
100.436792203
101.79
101.790392052
103.03
103.029351048
112.0
112.001470156
117.08
117.083398581
126.06
126.062285914
132.45
132.445119396
146.56
146.555065184
150.49
150.492755149
172.96
172.959257398
197.46
197.457172153
277.35
277.348106326
289.46
289.460756502
312.09
312.088270683
317.32
317.315355179
339.54
339.540473146
342.91
342.912528324
347.29
347.289392348
353.75
353.747365445
363.07
363.074738746
392.21
392.213953264
394.74
394.736509475
409.94
409.944818769
486.26
486.262619478
505.33
505.330024519
509.18
509.176849908
523.04
523.036920147
742.52
742.516682143
748.53
748.533523383
755.58
755.575802027
768.48
768.476323373
779.68
779.678950611
781.45
781.452805751
795.19
795.193286261
824.86
824.855063008

Thermoelectric properties [Reference]

Thermoelectric properties are calculated using BoltzTrap code [Source-code]. Electron and hole mass tensors (useful for semiconductors and insulators mainly)are given at 300 K [Source-code]. Following plots show the Seebeck coefficient and ZT factor (eigenvalues of the tensor shown) at 300 K along three different crystallographic directions. Seebeck coefficient and ZT plots can be compared for three different temperatures available through the buttons given below. Generally very high Kpoints are needed for obtaining thermoelectric properties. We assume the Kpoints obtained from above convergence were sufficient [Source-code].

WARNING: Constant relaxation time approximation (10-14 s) and only electronic contribution to thermal conductivity were utilized for calculating ZT.

Electron mass tensor (me unit)

0.5 0.0 -0.0
0.0 0.49 0.0
-0.0 0.0 0.44

Hole mass tensor (me unit)

2.25 0.0 -0.0
0.0 40.61 0.0
-0.0 0.0 6.89

n-& p-type Seebeck coeff. (µV/K), power-factor (µW/(mK2)), conductivity (1/(*m)), zT (assuming lattice part of thermal conductivity as 1 W/(mK)) at 600K and 1020 cm-3 doping. For mono/multi-layer materials consider Seebeck-coeff only.)

Property xx yy zz
n-Seebeck -123.32 -122.05 -112.17
n-PowerFactor 678.34 723.48 783.62
n-Conductivity 48572.06 51528.57 53913.07
n-ZT 0.25 0.27 0.28
p-Seebeck 368.15 391.07 405.96
p-PowerFactor 55.19 235.78 1425.81
p-Conductivity 360.91 1739.65 8651.42
p-ZT 0.03 0.14 0.82

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
Li-0.0-0.00.0-0.0
Li-0.00.00.00.0
O0.0-0.00.00.0
O0.0-0.00.0-0.0
O0.00.00.00.0
O0.0-0.00.0-0.0
O-0.0-0.00.0-0.0
O-0.0-0.00.0-0.0
O0.0-0.00.0-0.0
O0.0-0.00.0-0.0
As0.00.00.00.0
As0.00.00.00.0
Rb-0.00.0-0.0-0.0
Rb-0.00.0-0.00.0
Rb-0.0-0.0-0.0-0.0
Rb0.0-0.0-0.0-0.0

See also

Links to other databases or papers are provided below


mp-14363

ICSD-ID: 36644

AFLOW link

MP link
mp-14363

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