Questions tagged [fermi-energy]

Questions about or related to the Fermi energy.

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Question about determining Fermi energy in Quantum espresso

I used QE to calculate DOS for hBN. I expect to get results as shown here. The behavior of the computed DOS is as expected but QE gives Fermi energy = 1.974 eV. So, when I plot DOS concerning E-Ef, ...
Bekaso's user avatar
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4 votes
1 answer
627 views

Fermi Energy in Band Structure

I am new to this field and after going through some tutorials I was making band structure diagram of Silicon as shown in figure below, and the Fermi energy I got from SCF calculation is 6.208 eV. ...
karael's user avatar
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4 votes
1 answer
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How to find the Fermi energy with highest occupied and lowest unoccupied level from a single nscf caculation using quantum espresso?

Is it possible to find the Fermi energy with highest occupied and lowest unoccupied level from a single nscf caculation using quantum espresso?
SOELHADFI's user avatar
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5 votes
3 answers
163 views

How do I obtain CB and VB values from Quantum ESPRESSO?

Can someone explain to me please how am I supposed to get this: From this: I'm a little bit confused because in my calculations using Quantum ESPRESSO I found that: ...
Camilla's user avatar
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3 votes
1 answer
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Is it easier to obtain n-type TiO2 in reducing environment than in oxidizing environment?

In this paper "Role of Aluminum Doping in Anatase-to-Rutile Transformation from Thermodynamic View Point", the authors simulated different synthesis environment (either reducing or oxidizing)...
meTchaikovsky's user avatar
6 votes
1 answer
526 views

Fermi energy lower than valence band maximum?

I am trying to analyze the density of electronic states of a $\ce{TiO2}$ slab, but the result I got from VASP shows the fermi energy is lower than the valence band maximum (VBM) by a small energy ...
Jack's user avatar
  • 1,997
5 votes
0 answers
101 views

How does DFT decide the Fermi energy? [closed]

I am trying to figure out how density functional theory(DFT) decides the Fermi energy. As I understand, DFT could get the result of every orbital in the periodic system, then it could fulfill the ...
Jack's user avatar
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8 votes
2 answers
598 views

Mobility and chemical potential

I have been studying the Boltztrap2 software to calculate the thermoelectric properties of materials. However when following the tutorial given, the Seebeck coefficient is plotted against ...
Brian Lancaster's user avatar
6 votes
1 answer
670 views

SC vs NSC Fermi energy in VASP, which is correct?

While calculating the band structure using VASP, we usually take two steps: one is the self-consistent run to get the right CHGCAR file; and the other is a nonself-consistent calculation to generate ...
weipengchen's user avatar
8 votes
1 answer
588 views

If Gaussian and Tetrahedron smearing method lead to different Fermi energies, which one is the correct?

In addition to this post, The used settings were : DOS: ISMEAR = -5 SIGMA = 0.2 (default value) BS: ISMEAR = 0 SIGMA = 0.1 Now,...
Chi Kou's user avatar
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10 votes
1 answer
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How can I simulate the work function given by Ultraviolet Photoelectron Spectrum (UPS)?

How can I simulate the work function given by Ultraviolet Photoelectron Spectrum (UPS) of a molecule or a molecular crystal? I thought it is an easy job: Just do a geometry optimization and get the ...
Y. Zhai's user avatar
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6 votes
1 answer
849 views

Find the value of density of states at the Fermi energy using VASP

VASP has a tag NEDOS, which helps specify the # of points on which the DoS is evaluated. Other than that, we have EMIN and EMAX, which help decide the range of ...
Hitanshu Sachania's user avatar
14 votes
3 answers
2k views

Determining Fermi energy in density functional theory

Fermi energy is affected by the temperature and whether the material is an insulator/semiconductor/metal, but how is the Fermi energy determined in DFT calculations and how reliable are the obtained ...
Hitanshu Sachania's user avatar