[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 with HSE06. Can any one please suggest the calculations and properties that can be studied in the above mentioned case. -- Vipul S. Ghemud Ph.D. student. Dept of Physics, SPPU, Ganeshkhind, Pune- 411007. ___ Quantum ESPRESSO is supported by MaX (www.max-centre.eu/quantum-espresso) users mailing list users@lists.quantum-espresso.org https://lists.quantum-espresso.org/mailman/listinfo/users
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 = 1.0D-4, start = 0.0, finish = 1.5, step = 2.0D-4, broadening = 0.005, reference = 0.5, p_nbnd_occ = 4, p_nbnd_virt = 15, poor_of_ram = .false. poor_of_ram2 = .false. / ## I would like to mention that GGA file is converging but not giving any band gap (it is showing band crossing), so it'll not show any absorption coefficient. I am using QE 6.2.1 for HSE calculations, and they are converging very well, still i am getting following output: Program turboTDDFT v.6.1 (svn rev. 13369) starts on 21May2019 at 17:27:29 This program is part of the open-source Quantum ESPRESSO suite for quantum simulation of materials; please cite "P. Giannozzi et al., J. Phys.:Condens. Matter 21 395502 (2009); URL http://www.quantum-espresso.org;, in publications or presentations arising from this work. More details at http://www.quantum-espresso.org/quote Parallel version (MPI), running on56 processors R & G space division: proc/nbgrp/npool/nimage = 56 Reading data from directory: ./out1/cfts.save Info: using nr1, nr2, nr3 values from input Info: using nr1, nr2, nr3 values from input > Dear Vipul, > > > I run your test using QE 6.4.1 on my workstation with 8 cores. In the GGA > case, the > PWscf calculation did not converge after 100 iterations - so this is the > first > problem which you should solve before performing any linear-response > calculation > using the TDDFPT component of QE. In the case of hybrids (i.e. HSE) please > make sure > as well that the PWscf calculation converges with a required precision. > > > Concerning your input for the turbo_davidson.x code: please see example > TDDFPT/examples/example08 and read carefully the documentation in > TDDFPT/Doc. There > is no need to run turbo_spectrum.x after turbo_davidson.x (it is useful > only in > certain cases: see TDDFPT/examples/example08/run_example). > > > HTH > > > Regards, > > Iurii > > > -- > 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 -- Vipul S. Ghemud Ph.D. student. Dept of Physics, SPPU, Ganeshkhind, Pune- 411007. ___ Quantum ESPRESSO is supported by MaX (www.max-centre.eu/quantum-espresso) users mailing list users@lists.quantum-espresso.org https://lists.quantum-espresso.org/mailman/listinfo/users
Re: [QE-users] Absorption spectra of a bulk material
Thanks Iurii,
Following are my files:
scf:
calculation = 'scf',
restart_mode = 'from_scratch'
prefix='cfts',
verbosity = 'high',
pseudo_dir = '/home/alk1/vipul/pseudo',
outdir='./out'
etot_conv_thr= 1.0D-5
forc_conv_thr=1.0D-3
/
ibrav= 0,
celldm(1) = 10.5257190370006
nat= 16,
ntyp= 4,
ecutwfc=70,
input_dft='HSE'
nqx1=1,nqx2=1, nqx3=1,
exx_fraction=0.25,
screening_parameter=0.2,
exxdiv_treatment='vcut_ws',
x_gamma_extrapolation=.false,
ecutvcut=30
/
diagonalization = 'david'
mixing_mode = 'plain'
mixing_beta = 0.6
conv_thr = 1.0d-8
/
ATOMIC_SPECIES
Cu 63.549 Cu.pbe-mt_fhi.UPF
Sn 118.71 Sn.pbe-mt_fhi.UPF
Fe 55.845 Fe.pbe-mt_fhi.UPF
S 32.07 S.pbe-mt_fhi.UPF
ATOMIC_POSITIONS (angstrom)
Cu 02.785 2.771075
Cu 02.785 8.313225
Cu 2.7850 8.313225
Cu 2.7850 2.771075
Fe 00 0
Fe 2.7852.785 5.54215
Sn 00 5.54215
Sn 2.7852.785 0
S 4.3029506682 4.30295066829.7212817851
S 1.2670493318 1.26704933189.7212817851
S 4.3029506682 1.26704933181.3630182149
S 1.2670493318 4.30295066821.3630182149
S 1.5179506682 1.51795066824.1791317851
S 4.0520493318 4.05204933184.1791317851
S 1.5179506682 4.05204933186.9051682149
S 4.0520493318 1.51795066826.9051682149
K_POINTS {gamma}
CELL_PARAMETERS {alat}
1 0 0
0 1 0
0 0 1.99
###33
turbo_davidson (Input):
_input
prefix = 'cfts'
outdir = './out'
/
_dav
if_dft_spectrum = .true.
p_nbnd_occ = 10
p_nbnd_virt = 5
num_init = 30
/
(Output)
Program turboTDDFT v.6.1 (svn rev. 13369) starts on 8May2019 at 16: 2:30
This program is part of the open-source Quantum ESPRESSO suite
for quantum simulation of materials; please cite
"P. Giannozzi et al., J. Phys.:Condens. Matter 21 395502 (2009);
URL http://www.quantum-espresso.org;,
in publications or presentations arising from this work. More details at
http://www.quantum-espresso.org/quote
Parallel version (MPI), running on28 processors
R & G space division: proc/nbgrp/npool/nimage = 28
Reading data from directory:
./out/cfts.save
Message from routine read_xml_file:
file ./out/cfts.save not guaranteed to be safe for post-processing
Info: using nr1, nr2, nr3 values from input
Info: using nr1, nr2, nr3 values from input
turbo_spectrum (Input):
_input
prefix = 'cfts',
outdir ='./out',
itermax = 1
itermax0 = 1500
td = 'davidson'
end = 4.0
epsil = 0.004
increment = 0.001
start = 0.0
ipol = 4
plot_type = 2
eign_file = 'cfts-dft.eigen'
/
Note: I am running the jobs parallel on 1 node with 16 cores.
#
> Message: 10
> Date: Thu, 9 May 2019 09:58:05 +
> From: Timrov Iurii
> To: "users@lists.quantum-espresso.org"
>
> Subject: Re: [QE-users] Absorption spectra of a bulk material
> Message-ID:
> Content-Type: text/plain; charset="us-ascii"
>
> Dear Vipul,
>
>
> Please provide all input and output files of your calculations.
>
>
> - It is recommended to use the latest version of QE;
>
> - Concerning pseudos, have a look at SSSP:
> https://www.materialscloud.org/discover/sssp/table/efficiency
>
>
> Greetings,
>
> Iurii
>
>
> --
> 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
>
> From: users on behalf of Vipul
> Shivaji Ghemud
> Sent: Thursday, May 9, 2019 7:52:14 AM
> To: users@lists.quantum-espresso.org
> Subject: [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 coefficient of
> this system. I first run the scf, followed by turbo_davidson file and
> finally turbo_spectrum. But, while doing the turbo_davidson processing, I
> am getting following output and the run stops:
>
>
>
> " Program turboTDDFT v.6.1 (svn rev. 13369) starts on 8May2019 at 16:
> 2:30
>
> This program is part of the open-source Quantum ESPRESSO suite
> for quantum simulation of materials; please cite
> "P. Giannozzi et al., J. Phys.:Condens. Matter 21 395502 (2009);
> URL ht
[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 coefficient of this system. I first run the scf, followed by turbo_davidson file and finally turbo_spectrum. But, while doing the turbo_davidson processing, I am getting following output and the run stops: " Program turboTDDFT v.6.1 (svn rev. 13369) starts on 8May2019 at 16: 2:30 This program is part of the open-source Quantum ESPRESSO suite for quantum simulation of materials; please cite "P. Giannozzi et al., J. Phys.:Condens. Matter 21 395502 (2009); URL http://www.quantum-espresso.org;, in publications or presentations arising from this work. More details at http://www.quantum-espresso.org/quote Parallel version (MPI), running on28 processors R & G space division: proc/nbgrp/npool/nimage = 28 Reading data from directory: ./out/cfts.save Message from routine read_xml_file: file ./out/cfts.save not guaranteed to be safe for post-processing Info: using nr1, nr2, nr3 values from input Info: using nr1, nr2, nr3 values from input td.out (END) " I am getting the same message for GGA calculation also. I have given K_POINTS (GAMMA). Currently I am using .pbe-mt_fhi.UPF pseudopotential, what type of pseudopotential is to be used ? Please suggest where am I going wrong ? Thanks in advance -- Vipul S. Ghemud Ph.D. student. Dept of Physics, SPPU, Ganeshkhind, Pune- 411007. ___ Quantum Espresso is supported by MaX (www.max-centre.eu/quantum-espresso) users mailing list users@lists.quantum-espresso.org https://lists.quantum-espresso.org/mailman/listinfo/users
Re: [Pw_forum] Regarding controlled dynamics
Lorenzo I need the vacuum as I want to do thin film interface in order to mimic the experiments. I need to optimize the number of layers till which the strain remains, and yes I need the vacuum. I am not able to understand how to use the assume_isolated, ems_bc etc. flags to do the needy. Help is appreciated. --- > Hello, are you sure you need the vacuum? You can just alternate the two > materials and have 2 interfaces for the price of one. Also, vacuum in > plane > waves is not free. > >Regards > > -- > 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 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 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
[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 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
[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 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
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 restart and adding the K_POINTS and removing the hybrid flags. What else is to be done? >Dear Vipul, >if you don't do a nscf/band calculation, you will get the band structure on >the points of the regular grid you used for the scf calculation. This can >be >enough for computing the band gap, but won't make a nice plot. >kind regards -- >Dr. Lorenzo Paulatto >IdR @ IMPMC -- CNRS & Universit? Paris 6 >+33 (0)1 44 275 084 / skype: paulatz >http://www.impmc.upmc.fr/~paulatto/ >23-24/4?16 Bo?te courrier 115, >4 place Jussieu 75252 Paris C?dex 05 -- 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
[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 directly after scf with hybrid? Because hybrid flags are not compatible with NSCF, there is a huge difference in the energy levels also for scf (with HSE06) and nscf (without HSE06). -- 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
Re: [Pw_forum] Unit-cell and Super-cell bandgap difference
Thank you Dario, I'll take a run with same k-mesh. The energy of supercell is 0.4eV less than the 8times that of unit cell. I have just taken scf (without relax) > Dear Vipul, > There could be two main explanations for your results: > -A problem with the k-points you use to 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 7:47 AM, Vipul Shivaji Ghemud < > vi...@physics.unipune.ac.in> wrote: > 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.unipune.ac.in> wrote: > > > 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 > > electrons in the system, as the code QE considers unit-cell and > super-cell > > both a a single system? It's a bulk cubic system. I am facing similar > > problem with other systems also. -- 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
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.unipune.ac.in> wrote: > 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 > electrons in the system, as the code QE considers unit-cell and super-cell > both a a single system? It's a bulk cubic system. I am facing similar > problem with other systems also. > > > > -- > Vipul S. Ghemud > Ph.D. student. > Dept of Physics, > SPPU, Ganeshkhind, > Pune- 411007. > > -- 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
[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 electrons in the system, as the code QE considers unit-cell and super-cell both a a single system? It's a bulk cubic system. I am facing similar problem with other systems also. -- 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
[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 1000 iterations for the same temp. Also, how can we specify initial velocity? Please suggest the same. -- 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
[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. student. Dept of Physics, SPPU, Ganeshkhind, Pune- 411007. ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
[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 error can be removed, but i have to keep k-mesh and ecut same for the system. Is there anything else to be done?? Thank you in advance. -- 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
[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, screening_parameter=0.2, exxdiv_treatment='vcut_spherical', x_gamma_extrapolation=.false Is there anything else i need to add? -- 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
[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 Physics, SPPU, Ganeshkhind, Pune- 411007. ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
[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
