[Pw_forum] enthalpy in damped dynamic
Dear all, When I use bfgs algorithm for ion_dynamics in vc-relax calculation, the enthalpy is calculated and can be found in the output file. However, it seems that no enthalpy information is provided when damped dynamics are used. Why is it so? Thanks in advance, Amin -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20110528/ae0ef0d3/attachment.htm
[Pw_forum] problem on phonon
sir i am using quantum espresso 4.3 version i want to study the phase transition of yitrium nitride(yn) first by doing scf calculation at 0k i found a phase transition of B1 to B2 transition at 137 gpa for this i used a 14*14*14 kpoints mesh and convergence achived for scf is 10^-9 i used GGA psudo potentials of pbe type avalable in code of espresso website for y and n but when i did the calculation for phonon dispersion B2 stucter instablity (negative frequency ) in phonon spectrum continues upto 500 gpa why ? for this i used 4*4*4* mesh q points for dyanamical matrices i have incresed further but nothing results On Sat, May 28, 2011 at 9:36 PM, Stefano de Gironcoli wrote: > Dear Bhabya Sahoo, > >your very stingy use of punctuation make quite difficult (at least for > me) to follow your request... >Take your time and try to make you clear providing more detailed > information about your system, what is your aim, what is the problem, what > are the tests you have done. >No one is going to spend more time in thinking about your problem than > you do in explaining it. > >Please provide your affiliation. > >stefano > - > Stefano de Gironcoli, SISSA and DEMOCRITOS > > > On 05/28/2011 05:46 PM, bhabya sahoo wrote: > > i am using quantum espresso static calculation obeys thermdyanamic stability > transition from B1 to B2 transition at 138 gpa so ihave used 24 24 24 > kpoint grid for phonon in B2 phase is calculated 4 4 4 grid by linear > response calculation but why the instability (negative frequency in phonon ) > upto 450 gpa i have used pbe psudo potentials also the lattice constant is > exact for experimental data > can metastability have negative frequency so why this occures > optimisation is ok > other problem why free energy is not coming for unstable phase for qha code > in quantum espresso > replay immidiate if u have solution > On Sat, May 28, 2011 at 5:38 PM, bhabya sahoo > wrote: > > > sir > i used to calculate the phonon calculation on a 4*4*4 grid in cscl phase > but the unstability persists upto 500 gpa > but it is the thermodyanamic stability after 140 gpa kpoints 24*24*24 > what may be reseon i donot know > please help me > > > > ___ > Pw_forum mailing list > Pw_forum at pwscf.orghttp://www.democritos.it/mailman/listinfo/pw_forum > > > > ___ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > > -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20110528/da419bf8/attachment.htm
[Pw_forum] problem on phonon
i am using quantum espresso static calculation obeys thermdyanamic stability transition from B1 to B2 transition at 138 gpa so ihave used 24 24 24 kpoint grid for phonon in B2 phase is calculated 4 4 4 grid by linear response calculation but why the instability (negative frequency in phonon ) upto 450 gpa i have used pbe psudo potentials also the lattice constant is exact for experimental data can metastability have negative frequency so why this occures optimisation is ok other problem why free energy is not coming for unstable phase for qha code in quantum espresso replay immidiate if u have solution On Sat, May 28, 2011 at 5:38 PM, bhabya sahoo wrote: > sir > i used to calculate the phonon calculation on a 4*4*4 grid in cscl phase > but the unstability persists upto 500 gpa > but it is the thermodyanamic stability after 140 gpa kpoints 24*24*24 > what may be reseon i donot know > please help me > -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20110528/54fd37f5/attachment-0001.htm
[Pw_forum] How to obtain the binding energy ( in the unit of eV/Zn-O pair ) for Wurtsite ZnO?
On 05/28/2011 02:44 AM, mohnish pandey wrote:
> Dear Hongsheng,
> All the four bonds in ZnO wurtzite are equivalent.
But the four bonds have different bond lengths: the bond length parallel
to c axis is different from that of the other two bonds. Why can you
say are equivalent?
> So to calculate the binding energy you have to use the below formula :
> E_{binding-ZnO}=E{calculated-ZnO-wurtzite}-E_{Zn_{crystal-total}}-E_{E(1/2*O2}}.
> Remember that you have to do spin-polarised calculation for O2
> otherwise it will give wrong answer.
I've learned that this is due to O atom's open-shell configuration. Than
what is the initial spin should I use for O2?
Furthermore, for ZnO wurtzite, should I do spin-polarised calculation or
not?
> Binding energy definition is same as above. And cohesive energy is the
> difference in energy between the energy of crystal and corresponding
> species in isolated phases. Below are the some references.
Do you mean, for the calculation of cohesive energy, I should use the
big box model, then put one Zn in the big box, and O atom in another box
to obtain the total energy of each isolated phases?
> http://arxiv.org/ftp/cond-mat/papers/0610/0610002.pdf
> http://prb.aps.org/pdf/PRB/v70/i5/e054104
Regards.
--
Hongsheng Zhao
School of Physics and Electrical Information Science,
Ningxia University, Yinchuan 750021, China
[Pw_forum] question about the convergence of eigenvalues
Hello, dear pwscf users: I have a question about the convergence of eigenvalues. In section 11.1.0.24 of the user guide, it is mentioned that a warning of N eigenvectors not converged may signal serious trouble if it's presented in the last steps of self-consistency. (http://www.quantum-espresso.org/user_guide/node52.html#SECTION0001210240) But how about the non-scf calculations? In the bands and nscf calculations I got warning messanges as following: **example in band calculation (calculation = 'bands'): Computing kpt #:28 c_bands: 1 eigenvalues not converged **example in nscf calculation (calculation = 'nscf'): Computing kpt #: 144 c_bands: 2 eigenvalues not converged Are they acceptable? Thank you and best regards, Lun Yue -- Empfehlen Sie GMX DSL Ihren Freunden und Bekannten und wir belohnen Sie mit bis zu 50,- Euro! https://freundschaftswerbung.gmx.de
[Pw_forum] problem on phonon
Dear Bhabya Sahoo, your very stingy use of punctuation make quite difficult (at least for me) to follow your request... Take your time and try to make you clear providing more detailed information about your system, what is your aim, what is the problem, what are the tests you have done. No one is going to spend more time in thinking about your problem than you do in explaining it. Please provide your affiliation. stefano - Stefano de Gironcoli, SISSA and DEMOCRITOS On 05/28/2011 05:46 PM, bhabya sahoo wrote: > i am using quantum espresso static calculation obeys thermdyanamic stability > transition from B1 to B2 transition at 138 gpa so ihave used 24 24 24 > kpoint grid for phonon in B2 phase is calculated 4 4 4 grid by linear > response calculation but why the instability (negative frequency in phonon ) > upto 450 gpa i have used pbe psudo potentials also the lattice constant is > exact for experimental data > can metastability have negative frequency so why this occures > optimisation is ok > other problem why free energy is not coming for unstable phase for qha code > in quantum espresso > replay immidiate if u have solution > On Sat, May 28, 2011 at 5:38 PM, bhabya sahoo wrote: > >> sir >> i used to calculate the phonon calculation on a 4*4*4 grid in cscl phase >> but the unstability persists upto 500 gpa >> but it is the thermodyanamic stability after 140 gpa kpoints 24*24*24 >> what may be reseon i donot know >> please help me >> > > > ___ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20110528/a0b31bdf/attachment.htm
[Pw_forum] problem on phonon
Dear Sahoo, Without knowing your input file, how one can judge. Please provide your input file. Further, not fully optimization may be one reason. Best SKG Dept. of Phys. Bhavnagar University Gujarat On Sat, May 28, 2011 at 5:38 PM, bhabya sahoo wrote: > sir > i used to calculate the phonon calculation on a 4*4*4 grid in cscl phase > but the unstability persists upto 500 gpa > but it is the thermodyanamic stability after 140 gpa kpoints 24*24*24 > what may be reseon i donot know > please help me > > ___ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > > -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20110528/947b2660/attachment.htm
[Pw_forum] problem on phonon
sir i used to calculate the phonon calculation on a 4*4*4 grid in cscl phase but the unstability persists upto 500 gpa but it is the thermodyanamic stability after 140 gpa kpoints 24*24*24 what may be reseon i donot know please help me -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20110528/d72e13ef/attachment.htm
[Pw_forum] HSE
Hi Leonardo,
It is HSE06.
I'm not sure where you got the value 0.15 bohr^-1 for HSE06. You can
see in Krukau et al., JCP 125, 224106 (2006), that they say to use
0.11 bohr^-1 (or 0.15/sqrt(2)). (Also compare, in VASP they use 0.2
Angstrom^-1.) The same value is used for both PBE and HF parts.
Shameless plug: some small details about the implementation can also
be found in Komsa et al., PRB 81, 205118 (2010).
Best regards,
Hannu-Pekka Komsa
EPFL, Switzerland
> I would like to know exactly which "version" of HSE is implemented
> on Quantum-ESPRESSO.
> In the original HSE work a value for the screening parameter w is
> used, but on an errata another value is given.
>
> In recent publications they are usually called HSE03 (which uses
> w_{HF}=0.15/sqrt(2) and w_{PBE}=0.15 x 2^(1/3) ) and HSE06
> (w_{HF}=w_{PBE}=0.15).
>
> Looking at the code insde funct.f90 I found "screening_parameter =
> 0.106", which is the value of w_{HF} used on HSE03, which induces me
> to think that it's this "version" that is implemented.
> I couldn't find though if this value is used also for w_{PBE} (which
> would be a mistake) or not (and w_{PBE} is corrected at a later
> point in calculation).
>
> Can someone give me some info?
[Pw_forum] Insufficient q-points be calculated by phonon calculation
Dear all Thanks to all. I've run the job again and the problem has been disappeared. On Fri, May 27, 2011 at 7:38 PM, Seyed Mojtaba Rezaei Sani < s.m.rezaeisani at gmail.com> wrote: > This is the fourth time that I send the files. I guess the code does not > make *.dyn* for more than 9, i.e. two digit numbers. > > > On Fri, May 27, 2011 at 7:23 PM, Lorenzo Paulatto < > Lorenzo.Paulatto at impmc.upmc.fr> wrote: > >> On Fri, 27 May 2011 08:33:56 +0200, Seyed Mojtaba Rezaei Sani >> wrote: >> > *.dyn0 exists and I had sent it before. >> >> You did not send anything before. Apparently you forgot to attach the >> attachment. >> >> -- >> Lorenzo Paulatto IdR @ IMPMC/CNRS & Universit? Paris 6 >> phone: +33 (0)1 44275 084 / skype: paulatz >> www: http://www-int.impmc.upmc.fr/~paulatto/ >> mail: 23-24/4?16 Bo?te courrier 115, 4 place Jussieu 75252 Paris C?dex 05 >> ___ >> Pw_forum mailing list >> Pw_forum at pwscf.org >> http://www.democritos.it/mailman/listinfo/pw_forum >> > > > > -- > == > Seyed Mojtaba Rezaei Sani > Computational Condensed Matter Research Lab > Physics Department, Isfahan University of Technology > 84156-83111 Isfahan, Iran > Tel Lab: +98 311 391 3731 > s.rezaeisani at ph.iut.ac.ir > === > > -- == Seyed Mojtaba Rezaei Sani Computational Condensed Matter Research Lab Physics Department, Isfahan University of Technology 84156-83111 Isfahan, Iran Tel Lab: +98 311 391 3731 s.rezaeisani at ph.iut.ac.ir === -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20110528/2f8395e4/attachment.htm
[Pw_forum] The difference between binding energy and cohesive energy.
Hi all, Does the binding energy and cohesive energy mean the same thing or not? From here: http://www.physicsforums.com/showthread.php?t=300117 I find the following explains: Binding energy - the energy gained from chemical binding, usually measured against the element in its 'pure' form, e.g. an O2 molecule for oxygen. Cohesive energy - the binding energy for the atoms of a crystal, measured against the state of neutral free atoms. But, I also read some references which regards them as same thing. Any hints? Regards. -- Hongsheng Zhao School of Physics and Electrical Information Science, Ningxia University, Yinchuan 750021, China
[Pw_forum] How to obtain the binding energy ( in the unit of eV/Zn-O pair ) for Wurtsite ZnO?
Dear Hongsheng,
All the four bonds in ZnO wurtzite are equivalent. So to calculate the
binding energy you have to use the below formula :
E_{binding-ZnO}=E{calculated-ZnO-wurtzite}-E_{Zn_{crystal-total}}-E_{E(1/2*O2}}.
Remember that you have to do spin-polarised calculation for O2 otherwise it
will give wrong answer. Binding energy definition is same as above. And
cohesive energy is the difference in energy between the energy of crystal
and corresponding species in isolated phases. Below are the some references.
http://arxiv.org/ftp/cond-mat/papers/0610/0610002.pdf
<http://arxiv.org/ftp/cond-mat/papers/0610/0610002.pdf>
http://prb.aps.org/pdf/PRB/v70/i5/e054104
On Fri, May 27, 2011 at 12:19 PM, ?? ? wrote:
> Hi all,
>
> I want to obtain the binding energy ( in the unit of eV/Zn-O pair ) for
> Wurtsite ZnO. Considering that there are two different length of Zn-O bond,
> I cann't figure out how to calculate the binding energy in the unit ev/ZnO.
> Any hints on this issue?
>
> Regards.
> Hongsheng.
>
>
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum
>
>
--
Regards,
MOHNISH,
-
Mohnish Pandey
Y6927262,5th Year dual degree student,
Department of Chemical Engineering,
IIT KANPUR, UP, INDIA
-
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[Pw_forum] NEB error: unexpected dimension in ngg
I am performing a NEB calculation on a Fe-S system and after the calculation has run for a few hours I get the following error. task #22 from igk_l2g_kdip : error # 1 unexpected dimension in ngg Any help solving this problem would be greatly appreciated Pieter Barnard University of the Free State South Africa _ University of the Free State: This message and its contents are subject to a disclaimer. Please refer to http://www.ufs.ac.za/disclaimer for full details. Universiteit van die Vrystaat: Hierdie boodskap en sy inhoud is aan 'n vrywaringsklousule onderhewig. Volledige besonderhede is by http://www.ufs.ac.za/vrywaring beskikbaar. _ -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20110528/c0d13d0f/attachment.htm
[Pw_forum] energy/force/stress obtained from scf versus vc-relax
Dear Amin: On Sat, May 28, 2011 at 2:26 AM, Amin Torabi wrote: > Dear all, > > I did a vc-relax calculation. Then, I used the cell_parameters and > atomic_positions obtained at the end of vc-relax to do an scf calculation. I > didn't change any other settings, like k-point or ecutoff. > However, the total energy, the total force and the total stress obtained > from the scf calculation are different form the values obtained at the end > of the vc-relax calculation. (The vc-relax values are lower.) > Why is it so? > You are right. When you do vc-relax, the G points contained in wave-function does not change with the cell parameters(That means the energy cutoff changes when cell parameters change during vc-relax). When you do scf after vc-relax, the cell parameters of scf is different from that of vc-relax. Therefore, the G points contained in wave-function of scf differs from that of vc-relax. Usually, you should do the second vc-relax if the cell parameters change a lot. After the second vc-relax, the force/stress of scf will be close to that of second vc-relax. > > > Thanks is advance. > > Amin > > ___ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > > -- Hui Wang School of physics, Fudan University, Shanghai, China -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20110528/a882f756/attachment.htm
[Pw_forum] Electro-optical coefficients
On May 27, 2011, at 20:48 , Antonio wrote: > Somebody knows how to calculate the electro-optical coefficients (i.e. > beta) by the phonon code for the Raman calculation within PWSCF? elop=.true. (see example15) P. --- Paolo Giannozzi, Dept of Chemistry&Physics&Environment, Univ. Udine, via delle Scienze 208, 33100 Udine, Italy Phone +39-0432-558216, fax +39-0432-558222
[Pw_forum] Invitation to connect on LinkedIn
LinkedIn BAC PHUNG requested to add you as a connection on LinkedIn: -- veronica, I'd like to add you to my professional network on LinkedIn. - BAC Accept invitation from BAC PHUNG http://www.linkedin.com/e/-iqpnjm-go80cfhj-2s/XAAkmOm8d3sw5mZYSULFbcFqV9UKwx/blk/I50390134_60/pmpxnSRJrSdvj4R5fnhv9ClRsDgZp6lQs6lzoQ5AomZIpn8_c3pvd3cNc3APc3l9bQxjrDlip4AUbPgVejgTejAOc3cLrCBxbOYWrSlI/EML_comm_afe/ View invitation from BAC PHUNG http://www.linkedin.com/e/-iqpnjm-go80cfhj-2s/XAAkmOm8d3sw5mZYSULFbcFqV9UKwx/blk/I50390134_60/0MdBYQcP4MejcMdkALqnpPbOYWrSlI/svi/ -- DID YOU KNOW that LinkedIn can find the answers to your most difficult questions? Post those vexing questions on LinkedIn Answers to tap into the knowledge of the world's foremost business experts: http://www.linkedin.com/e/-iqpnjm-go80cfhj-2s/ask/inv-23/ -- (c) 2011, LinkedIn Corporation -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20110528/63e41fd7/attachment.htm
[Pw_forum] HSE
Hi,
I would like to know exactly which "version" of HSE is implemented on
Quantum-ESPRESSO.
In the original HSE work a value for the screening parameter w is used, but on
an errata another value is given.
In recent publications they are usually called HSE03 (which uses
w_{HF}=0.15/sqrt(2) and w_{PBE}=0.15 x 2^(1/3) ) and HSE06
(w_{HF}=w_{PBE}=0.15).
Looking at the code insde funct.f90 I found "screening_parameter = 0.106",
which is the value of w_{HF} used on HSE03, which induces me to think that it's
this "version" that is implemented.
I couldn't find though if this value is used also for w_{PBE} (which would be a
mistake) or not (and w_{PBE} is corrected at a later point in calculation).
Can someone give me some info?
Thanks,
Leonardo Jorge
PhD Student
Instituto de F?sica, Universidade de S?o Paulo, Brazil
