JVASP-25573_K3Np(H3O4)2
JARVIS-ID:JVASP-25573 Functional:optB88-vdW Primitive cell Primitive cell Conventional cell Conventional cell
Chemical formula:K3Np(H3O4)2 Formation energy/atom (eV):na a 7.583 Å α:90.0 ° a 7.583 Å α:90.0 °
Space-group :P2_1/c, 14 Relaxed energy/atom (eV):-4.6336 b 8.264 Å β:117.073 ° b 8.264 Å β:117.073 °
Calculation type:Bulk SCF bandgap (eV):1.43 c 7.816 Å γ:90.0 ° c 7.816 Å γ:90.0 °
Crystal system:monoclinic Point group:2/m Density (gcm-3):3.72 Volume (3):436.11 nAtoms_prim:36 nAtoms_conv:36
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): 1.403I


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 : 1.4301 eV

Static real-parts of dielectric function in x,y,z: 3.72,4.11,3.34


Optoelectronic properties METAGGA-MBJ [Reference]

Single point DFT calculation was carried out with meta-gga MBJ potential [Source-code]. 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. Also, ionic contributions were neglected.

MBJ bandgap is : 1.5993 eV

Static real-parts of dielectric function in x,y,z: 3.19,3.51,2.84


Solar-cell SLME [Reference]

Theoretical solar-cell efficiency (in %) was calculated using spectroscopy limited maximum efficiency (SLME) and TBmBJ for the material with 500 nm thickness and at 300 K. Note that generally there are many factors that contribute towards the efficiency, such as carrier effective mass etc.

SLME is: 30.4


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): 39.01 GPa, Voigt-shear modulus (GV): 18.13 GPa

Reuss-bulk modulus (KR): 37.63 GPa, Reuss-shear modulus (GR): 15.69 GPa

Poisson's ratio: 0.31, Elastic anisotropy parameter: 0.81

Clarke's lower limit of thermal conductivity (W/(m.K)): 0.79

Cahill's lower limit of thermal conductivity (W/(m.K)): 0.88

Elastic tensor
68.2 20.6 13.7 0.0 0.4 -0.0
20.6 78.3 36.4 0.0 4.1 -0.0
13.7 36.4 63.2 -0.0 -1.7 -0.0
0.0 0.0 -0.0 13.2 0.0 1.7
0.4 4.1 -1.7 0.0 20.4 0.0
0.0 -0.0 -0.0 1.7 0.0 10.7

Phonon mode (cm-1)
-0.15
-0.11
0.01
38.03
56.05
66.69
78.71
79.56
87.87
88.75
97.79
103.54
107.15
108.65
114.35
115.85
118.77
121.79
123.88
125.97
127.75
136.34
137.2
139.09
142.8
148.35
148.73
153.52
154.84
156.46
158.04
162.21
173.3
176.88
183.3
187.31
195.97
198.78
200.45
203.9
215.66
224.18
237.97
244.24
246.26
247.27
251.29
251.72
270.1
275.7
282.47
284.82
284.99
292.06
296.44
299.39
313.71
314.85
330.1
334.52
408.6
431.06
432.29
433.13
505.25
517.56
538.4
542.85
693.1
693.81
721.71
723.4
726.69
731.54
744.85
748.89
759.2
770.09
775.34
781.56
784.76
786.96
819.24
819.85
841.78
859.72
865.09
868.93
874.42
889.57
891.89
897.07
1578.33
1580.16
1658.88
1660.3
3023.33
3024.31
3028.78
3028.83
3262.36
3264.36
3264.49
3269.43
3323.89
3327.93
3328.18
3367.39

Point group

point_group_type: 2/m

Visualize Phonons here
Phonon mode (cm-1) Representation
-0.15
-0.1474746219
-0.11
-0.1128331755
0.01
0.0104503678
38.03
38.0283922882
56.05
56.0507338599
66.69
66.689039805
78.71
78.7066052013
79.56
79.5578372249
87.87
87.8749072325
88.75
88.7521778422
97.79
97.7906728731
103.54
103.537252452
107.15
107.146483903
108.65
108.649782715
114.35
114.34676187
115.85
115.850299151
118.77
118.771480714
121.79
121.785173513
123.88
123.879883531
125.97
125.97370432
127.75
127.747868813
136.34
136.337742756
137.2
137.195555673
139.09
139.090820512
142.8
142.803499353
148.35
148.351494815
148.73
148.73232152
153.52
153.516111655
154.84
154.843851645
156.46
156.455013039
158.04
158.041004082
162.21
162.205128189
173.3
173.296090327
176.88
176.875742451
183.3
183.297453507
187.31
187.309460561
195.97
195.965155513
198.78
198.782664293
200.45
200.448842793
203.9
203.901809231
215.66
215.656167587
224.18
224.180066589
237.97
237.968488925
244.24
244.240270145
246.26
246.262828617
247.27
247.274816199
251.29
251.294717609
251.72
251.717720332
270.1
270.100598411
275.7
275.702286076
282.47
282.471349419
284.82
284.821901845
284.99
284.994592918
292.06
292.061110049
296.44
296.439359333
299.39
299.392339155
313.71
313.708961042
314.85
314.846525266
330.1
330.099519126
334.52
334.524107615
408.6
408.604859297
431.06
431.056939785
432.29
432.290415458
433.13
433.133858841
505.25
505.248857578
517.56
517.561545091
538.4
538.404149859
542.85
542.852408212
693.1
693.101072341
693.81
693.810320218
721.71
721.706774731
723.4
723.401204623
726.69
726.6854419
731.54
731.535398517
744.85
744.85217971
748.89
748.889009104
759.2
759.202961537
770.09
770.085354079
775.34
775.342759631
781.56
781.559524828
784.76
784.758717363
786.96
786.964517405
819.24
819.244663982
819.85
819.852014047
841.78
841.778327239
859.72
859.720310569
865.09
865.092802682
868.93
868.92763887
874.42
874.424997883
889.57
889.572515148
891.89
891.88759544
897.07
897.07205646
1578.33
1578.3338547
1580.16
1580.15978136
1658.88
1658.88463066
1660.3
1660.30005889
3023.33
3023.33009575
3024.31
3024.30504901
3028.78
3028.7785041
3028.83
3028.82678811
3262.36
3262.3634153
3264.36
3264.36084193
3264.49
3264.48761165
3269.43
3269.42688274
3323.89
3323.88652675
3327.93
3327.92934719
3328.18
3328.17637662
3367.39
3367.3863211

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)

3377.56 0.0 -0.0
0.0 5026.66 -2408.05
-0.0 -2408.05 12807.47

Hole mass tensor (me unit)

2.57 -0.0 0.0
-0.0 4.71 -2.56
0.0 -2.56 7.57

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 -396.26 -394.49 -388.44
n-PowerFactor 0.17 0.49 0.67
n-Conductivity 1.06 3.25 4.28
n-ZT 0.0 0.0 0.0
p-Seebeck 316.85 325.96 325.99
p-PowerFactor 135.64 355.89 527.0
p-Conductivity 1325.25 3493.64 4960.11
p-ZT 0.08 0.21 0.31

See also

Links to other databases or papers are provided below


mp-557615

ICSD-ID: 161584

AFLOW link

MP link
mp-557615

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