Questions tagged [bandgap]
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What's the meaning of a Hubbard term determined by repeated investigation?
In the paper bellow they used GGA+U to investigate the structural, electronic and
optical properties of Ag- and Cu-doped ZnO.
https://www.emerald.com/insight/content/doi/10.1108/MI-05-2022-0088/full/...
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How to determine high-symmetry points in case of PBE0 using Quantum ESPRESSO?
Normally when we use PBE-GGA as an approximation we can determine the high symmetry points in x coordinate from the output file of bands.x calculation . But in the ...
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Extracting band structure data using Boltztrap for Quantum ESPRESSO
I used PBE0 in my calculations using Quantum ESPRESSO . I have ran a scf calculation then I used Boltztrap by running the command btp2 -vv interpolate -m 3 ./ then <...
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Optical Band gap determination from absorption coeffecient using DFT
I am currently working with a perovskite material which shows forbidden transitions. Older studies used bigger values of $\alpha$ in HSE06 calcualtions(to match with experimental Band Gap) but a ...
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Do the orbital energies of ground-state Dyson orbitals exactly capture arbitrary excitation energies and/or ionisation potentials/electron affinities?
According to an answer to my question on whether the Kohn-Sham orbital energies theoretically exactly capture arbitrary ionisation potentials and/or excitation energies, the answer is no for both ...
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Question on generalised Kohn-Sham "band gap"
It is often said that the optical band gap, i.e. the first excitation energy, of a species is exactly equal to the difference between the (Kohn-Sham) HOMO and LUMO. This would mean that the state of ...
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Direct and Indirect bandgap
How can I know which one is direct bandgap material and which one is indirect?
Why does Germanium have an indirect bandgap? How can be it become a direct bandgap material?
Here, I have attached a ...
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The comparison of bandgap value of slab and bulk phase [closed]
I tried to calculate the bandgap of the TiO2-Rutile bulk phase, DFT(not +U) calculation shows the bandgap is about 1.8eV, which is roughly the same as the 1.78eV on the Material Project. When ...
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How would surface state affect the band gap value of semiconductors? [closed]
I am struggling to figure out the relationship between bandgap value and surface states. To my understanding, when considering the material that includes surface, there would be some surface states in ...
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How to get the right type of bandgap(indirect/direct) in VASP? [closed]
I am trying to calculate the band gap type(Direct or Indirect) of TiO2-Rutile, according to the Material Project, rutile is a direct bandgap type semiconductor. The VBM and CBM are both at the Gamma ...
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What parameters should be checked on both unit cell and super cell to make sure the calculations are going fine?
Question is based on further learning about the previously asked question - Do NSCF calculations on Supercell gives different band gap than the Unit Cell?
How should I compare SCF and NSCF ...
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