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Structural formula: Zr2 I4

Functional: optB88-vDW

Space group : P2_1/m

Calculation type: 1L

JARVIS ID: JVASP-13508

Formation energy/atom (eV): -0.849

Relaxed energy/atom (eV): -2.478

SCF bandgap (eV): 0.027

Primitive cell lattice parameters

a 6.876 Å , b 3.763 Å , c 27.093 Å

α 90.0 ° , β 94.746 ° , γ 90.0 °

Conventional cell lattice parameters

a 6.876 Å , b 3.763 Å , c 27.093 Å

α 90.0 ° , β 94.746 ° , γ 90.0 °

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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. 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.

Bandgap (eV): 0.0291D

Electrostatic potential

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.

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.

Thermoelectric properties

Thermoelectric properties are calculated using BoltzTrap code. Electron and hole mass tensors are given at 300 K. 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.

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)

0.315417866284 -1.65172681106e-18 0.0138143295689
-1.65172681106e-18 0.10898023595 3.76057183346e-18
0.0138143295689 3.76057183346e-18 278.918878262

Hole mass tensor (me unit)

0.291566626954 -8.20257868774e-19 0.0123568706141
-8.20257868774e-19 0.129849396946 3.89595987712e-18
0.0123568706141 3.89595987712e-18 289.980257512

Magnetic moment

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.

-0.000 μB

Reference