[QE-users] Semi-conductor Calculations

I have a semiconductor system which shows conducting nature with GGA calculations and shows a band gap with HSE06 (as expected). Which calculations can I perform to study the system to compare with experimental findings? I am facing limitations as many of the QE calculations are not compatible

Re: [QE-users] Absorption spectra of a bulk material

Dear Iurii, In accordance with the previous suggestions I have changed my TD file but still facing same problem. TD file is as below: _input prefix = 'cfts' outdir = './out1' restart = .false. / _dav num_eign = 10, num_init = 20, num_basis_max = 80, residue_conv_thr =

Re: [QE-users] Absorption spectra of a bulk material

gt; > -- > Dr. Iurii Timrov > Postdoctoral Researcher > STI - IMX - THEOS and NCCR - MARVEL > Swiss Federal Institute of Technology Lausanne (EPFL) > CH-1015 Lausanne, Switzerland > +41 21 69 34 881 > http://people.epfl.ch/265334 > > Fr

[QE-users] Absorption spectra of a bulk material

Dear all, For a system (experimentally which is semi-conductor) with GGA calculation I am getting band crossing i.e., no band gap. But, when I add HSE flags I get around 2 eV gap (which is desired). I have optimized the parameters and K-mesh (6 6 3 0 0 0). I want to calculate absorption

Re: [Pw_forum] Regarding controlled dynamics

Lorenzo Paulatto > Written on a virtual keyboard with real fingers > > On 20 May 2017 2:52 p.m., "Vipul Shivaji Ghemud" < > vi...@physics.unipune.ac.in> wrote: > > Hi all, > I am planing to work on interfaces. In doing so, I want to keep few layers > of a struct

[Pw_forum] Regarding controlled dynamics

Hi all, I am planing to work on interfaces. In doing so, I want to keep few layers of a structure fixed while few to relax. In short this is what I am planning : 10A vacuum 2layers fixed 4layers to relax 2layers fixed How can I do this type of controlled dynamics? Thanx in advance. -- Vipul

[Pw_forum] Absolute energy values

Hi all, how do we get absolute energy values (HOMO, LUMO, Fermi) in QE? From what I understand the values in the output are relative values and not absolute. In VASP (other DFT based software) there is a formula for getting absolute values, is there any solution in QE also? -- Vipul S. Ghemud

Re: [Pw_forum] Bandstructure with HSE06

Thank you Lorenzo, but I am still having doubt. As per your guideline, I should run nscf, but when I do it, the energy of states is much less than the hybrid scf (it is comparable to GGA scf), so it may happen that I get wrong bands. I am changing the calculation to nscf or bands, restart mode to

[Pw_forum] Bandstructure with HSE06

Hi all, I wanted to do bandstructure calculation with HSE06. Is it necessary to do nscf (calculation = bands), and then move on to bands.in and plotband.in. Or, as we do in case of DOS i.e. nscf is not needed if we add hybrid to our calculation, we can directly run dos; do we move to bands.in

Re: [Pw_forum] Unit-cell and Super-cell bandgap difference

o compute the bandstrucure: the > > grid > for the cell and supercell must be consistent > -An error in the supercell. Try comparing total energies: does the > supercell have 8 times the total energy of the cell? > Best, > Dario Rocca > On Fri, Nov 25, 2016 at 7:4

Re: [Pw_forum] Unit-cell and Super-cell bandgap difference

I have been using 8*8*8 for unit cell and 4*4*4 for supercell as my supercell is 2*2*2 unit cell. > Dear Vipul, > how many k-points did you use for the cell and for the supercell > Best > Dario > On Thu, Nov 24, 2016 at 6:23 AM, Vipul Shivaji Ghemud < > vi...@physics.unipun

[Pw_forum] Unit-cell and Super-cell bandgap difference

Hi all, I am working on a system of 9atoms in a unit-cell having bandgap of 3.5eV; but I am considering the super-cell(4 unit-cells) then the bandgap is reduced by ~0.45eV for HSE06. The bandgaps are similar with GGA. Is it due to the exchnage-correlation contribution of the increased number of

[Pw_forum] Velocity and Temperature control in MD

Hi all, I want to do MD for my system. In this I want to raise the temperature of the system above its melting point (say 500K) and then hold it there for next 1000 iterations at same temperature. I have tried raising the temperature but I don't know how to hold it at specific temp and do further

[Pw_forum] Regarding Absolute band-edges

Hi all, How can we get absolute band-edges in QE to compare with the experimental values? For quantum dots we have scissor operator to shift the homo level. But, i have got expected bandgap, but need to find absolute band-edges. What is the shift for homo and lumo. -- Vipul S. Ghemud Ph.D.

[Pw_forum] Error in g-vectors

I am doing a vc-relax calculation but i am getting two different errors for two different calculations. 1. Error in routine ggen (**): too many g-vectors 2. Error in routine ggen (80): g-vectors missing ! Please guide me through. I have read that by changing the ecutwfc the

[Pw_forum] Incomplete output in HSE calculation

I am doing HSE calculation, and using following flags. But, the output reads: the Fermi energy is 7.8327 ev convergence has been achieved in 33 iterations But, it is not writing Total energy and other outputs. The input is as follows: input_dft='HSE' exx_fraction=0.25,

[Pw_forum] Ionization in QE

I want to ionize my cluster i.e. I want to remove an electron from overall structure and not a specific atom, so that the charge distribution is uniform and overall charge is less by the charge of 1 electron. Similarly, I want to do it for cation -- Vipul S. Ghemud Ph.D. student. Dept of

[Pw_forum] Partial Charge Density in QE

Can we get partial charge density in quantum espresso? If yes, how? -- Vipul S. Ghemud Ph.D. student. Dept of Physics, SPPU, Ganeshkhind, Pune- 411007. ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum