[Pw_forum] How to get the most reliable dos/pdos results
what information do you want to obtain ? is the result you get stable (in the sense that does not change significantly) if you increase the number of k-points or vary degauss a bit ? pdos are a (quite) arbitrary way of decomposing dos in atomic and angular contributions. don't overestimate their information content. don't believe in exact numbers, but try to get a feeling of the trends.. believe in the results to the extent they do not depend seriously on the details of the calculations. hope this helps stefano donsity of state, projected densi On 06/03/2012 04:37 PM, Peng Chen wrote: > Dear Stefnao, > > Thanks for your reply. Energy convergence (to 0.002 Ry) tests with a series > of ecutwfc, erho, degauss, kpoints parameters have been done (I am not sure > if there are other convergence tests for DOS). The experimental result will > be available later, I just want to make sure I am not doing something wrong > with choosing parameters. Someone told me to compare with all-electron > calculation results. I actually did it with Exciting code, but it was > running for two weeks and a power outage occurred... > > On Sun, Jun 3, 2012 at 2:40 AM, Stefano Baroni wrote: > >> Dear Peng, >> >> I do not know nor anybody here (nor elsewhere) could. Suppose somebody >> does and tells you "3". What use would you do of that info? Would you use >> "3" and justify your choice by the advice of Mr. XXX as read on mailing >> list YYY? >> >> The correct way to proceed is: 1) form an idea of the level of accuracy >> you need; 2) perform a convergence test until your target accuracy is met; >> 3) stop there and don't ask for more accuracy than you actually need, >> unless you want to test a specific algorithm/code and your level of >> understanding of it. >> >> Good luck! >> SB >> >> On Jun 3, 2012, at 4:44 AM, Peng Chen wrote: >> >> Dear QE users, >> >> I tried several dos/pdos calculations with different parameters listed in >> the table below. The results are a little different. >> I am not sure which result is more reliable when the experimental results >> are not available. >> >> scf >> nscf >> 1. dos/pdos smearing (mv,degauss=0.01) tetrahedra >> 2. dos/pdos smearing (mv,degauss=0.01) smearing >> (mv,degauss=0.01) >> 3. dos tetrahedra >> tetrahedra >> pdos smearing (mv,degauss=0.01) smearing >> (mv,degauss=0.01) >> >> >> >> -- >>Best Regards. >> Peng >> ___ >> Pw_forum mailing list >> Pw_forum at pwscf.org >> http://www.democritos.it/mailman/listinfo/pw_forum >> >> >> --- >> Stefano Baroni - SISSA& DEMOCRITOS National Simulation Center - Trieste >> http://stefano.baroni.me [+39] 040 3787 406 (tel) -528 (fax) / >> stefanobaroni (skype) >> >> La morale est une logique de l'action comme la logique est une morale de >> la pens?e - Jean Piaget >> >> >> ___ >> Pw_forum mailing list >> Pw_forum at pwscf.org >> http://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/20120603/8065d308/attachment.htm
[Pw_forum] Trying to Generate a Pseudo-Hydrogen Pseudopotential
Hello, I've never tried to generate a pseudopotential before, so this is all very new to me. I'm trying to construct a PW91 PP for a Z=5/4 pseudo hydrogen atom. I've studied the tutorials that I've been able to find and also the write-up on LD1 in the recently-released QE 5.0 package. Here is the input file that I'm using: title='PW91 PP for Z=5/4 Pseudo-Hydrogen', zed=1.25, iswitch=3, nld=3, rlderiv=1.20, eminld=-0.5, emaxld=0.5, deld=0.002, rel=0, dft='pw91', verbosity='high', config='1s1.25' / zval=1.25, pseudotype=3, file_pseudopw='H.pw91-rrkj-van-125.UPF', lloc=-1, rcloc=1.20, nlcc=.false., author='VicBermudez' / 1 1S 1 0 1.25 0.00 1.20 1.20 - and here is the error message that results - from ld1_readin : error # 1 wrong nuclear charge zed: 1.25 stopping ... If, in place of zed=1.25, I use atom='H', I get a message complaining about a conflict between the input charge (1) and the computed charge (1.25). In spite of a previous forum exchange indicating that the presently-available PZ PPs are adequate for pseudo-Hs in GGA calculations, I would nevertheless like to generate one of my own as a learning experience. Can someone please point me in the right direction ? Thanks, Vic Bermudez Victor M. Bermudez Code 6876 U.S. Naval Research Laboratory 4555 Overlook Ave., S.W. Washington, DC 20375-5347 Phone: 202-767-6728 FAX: 202-767-1165 E-mail: victor.bermudez at nrl.navy.mil
[Pw_forum] How to get the most reliable dos/pdos results
Hello All, I like to thank Dr. Stafano for his advices, I think they are useful to all of us. Kindest Regards, IYAD On Sun, Jun 3, 2012 at 2:40 AM, Stefano Baroni wrote: > Dear Peng, > > I do not know nor anybody here (nor elsewhere) could. Suppose somebody > does and tells you "3". What use would you do of that info? Would you use > "3" and justify your choice by the advice of Mr. XXX as read on mailing > list YYY? > > The correct way to proceed is: 1) form an idea of the level of accuracy > you need; 2) perform a convergence test until your target accuracy is met; > 3) stop there and don't ask for more accuracy than you actually need, > unless you want to test a specific algorithm/code and your level of > understanding of it. > > Good luck! > SB > > On Jun 3, 2012, at 4:44 AM, Peng Chen wrote: > > Dear QE users, > > I tried several dos/pdos calculations with different parameters listed in > the table below. The results are a little different. > I am not sure which result is more reliable when the experimental results > are not available. > > scf > nscf > 1. dos/pdos smearing (mv,degauss=0.01) tetrahedra > 2. dos/pdos smearing (mv,degauss=0.01) smearing > (mv,degauss=0.01) > 3. dos tetrahedra >tetrahedra > pdos smearing (mv,degauss=0.01) smearing > (mv,degauss=0.01) > > > > -- > Best Regards. > Peng > ___ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > > > --- > Stefano Baroni - SISSA & DEMOCRITOS National Simulation Center - Trieste > http://stefano.baroni.me [+39] 040 3787 406 (tel) -528 (fax) / > stefanobaroni (skype) > > La morale est une logique de l'action comme la logique est une morale de > la pens?e - Jean Piaget > > > ___ > 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/20120603/ccb62722/attachment-0001.htm
[Pw_forum] How to get the most reliable dos/pdos results
Dear Stefnao, Thanks for your reply. Energy convergence (to 0.002 Ry) tests with a series of ecutwfc, erho, degauss, kpoints parameters have been done (I am not sure if there are other convergence tests for DOS). The experimental result will be available later, I just want to make sure I am not doing something wrong with choosing parameters. Someone told me to compare with all-electron calculation results. I actually did it with Exciting code, but it was running for two weeks and a power outage occurred... On Sun, Jun 3, 2012 at 2:40 AM, Stefano Baroni wrote: > Dear Peng, > > I do not know nor anybody here (nor elsewhere) could. Suppose somebody > does and tells you "3". What use would you do of that info? Would you use > "3" and justify your choice by the advice of Mr. XXX as read on mailing > list YYY? > > The correct way to proceed is: 1) form an idea of the level of accuracy > you need; 2) perform a convergence test until your target accuracy is met; > 3) stop there and don't ask for more accuracy than you actually need, > unless you want to test a specific algorithm/code and your level of > understanding of it. > > Good luck! > SB > > On Jun 3, 2012, at 4:44 AM, Peng Chen wrote: > > Dear QE users, > > I tried several dos/pdos calculations with different parameters listed in > the table below. The results are a little different. > I am not sure which result is more reliable when the experimental results > are not available. > > scf > nscf > 1. dos/pdos smearing (mv,degauss=0.01) tetrahedra > 2. dos/pdos smearing (mv,degauss=0.01) smearing > (mv,degauss=0.01) > 3. dos tetrahedra >tetrahedra > pdos smearing (mv,degauss=0.01) smearing > (mv,degauss=0.01) > > > > -- > Best Regards. > Peng > ___ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > > > --- > Stefano Baroni - SISSA & DEMOCRITOS National Simulation Center - Trieste > http://stefano.baroni.me [+39] 040 3787 406 (tel) -528 (fax) / > stefanobaroni (skype) > > La morale est une logique de l'action comme la logique est une morale de > la pens?e - Jean Piaget > > > ___ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > > -- Best Regards. Peng -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20120603/01dc4f35/attachment.htm
[Pw_forum] Finite Temperature Schr?dinger Equation.
Dear Hongsheng Zhao, I don't think that the quoted paper is reliable. Inclusion of temperature effects into DFT is still a present issue and undergoes heavy research. However, some really good publications are: - N. D. Mermin, Phys. Rev. 137, A1441 (1965) - Helmut Eschrig, Phys. Rev. B 82, 205120 (2010), (see also Physics Viewpoint http://physics.aps.org/articles/v3/99) - Pittalis et al., Phys. Rev. Lett. 107, 163001 (2011) A possible workaround would be the usage of ab-initio molecular dynamics or the the explicit inclusion of phonons/electron-phonon-coupling and Boltzmann transport. bests NFH - Nicki Frank Hinsche, Dipl. Phys. Institute of physics - Theoretical physics, Martin-Luther-University Halle-Wittenberg, Von-Seckendorff-Platz 1, Room 0.20 D-06120 Halle/Saale, Germany Tel.: ++49 345 5525434 nicki.hinsche at physik.uni-halle.de - Fellow of the International Max Planck Re- search School-MPI for Microstructure Physics - > Hi all, > > I've learned that the "Finite Temperature Schr?dinger Equation" from > here: > > http://arxiv.org/abs/1005.2751 > > Basically, I've two issues on the above paper: > > 1- Does someone has any hints on how to realize it in pwscf? > > 2- Besides this method, are there other methods for taking the > temperature into effect within Schr?dinger Equation? Which is the > most > feasible schedule till now? > > Regards > -- > Hongsheng Zhao > School of Physics and Electrical Information Science, > Ningxia University, Yinchuan 750021, China -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20120603/24d1aefe/attachment.htm
[Pw_forum] How to get the most reliable dos/pdos results
Dear Peng, I do not know nor anybody here (nor elsewhere) could. Suppose somebody does and tells you "3". What use would you do of that info? Would you use "3" and justify your choice by the advice of Mr. XXX as read on mailing list YYY? The correct way to proceed is: 1) form an idea of the level of accuracy you need; 2) perform a convergence test until your target accuracy is met; 3) stop there and don't ask for more accuracy than you actually need, unless you want to test a specific algorithm/code and your level of understanding of it. Good luck! SB On Jun 3, 2012, at 4:44 AM, Peng Chen wrote: > Dear QE users, > > I tried several dos/pdos calculations with different parameters listed in the > table below. The results are a little different. > I am not sure which result is more reliable when the experimental results are > not available. > > scf > nscf > 1. dos/pdos smearing (mv,degauss=0.01) tetrahedra > 2. dos/pdos smearing (mv,degauss=0.01) smearing > (mv,degauss=0.01) > 3. dos tetrahedra > tetrahedra > pdos smearing (mv,degauss=0.01) smearing > (mv,degauss=0.01) > > > > -- > Best Regards. > Peng > ___ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum --- Stefano Baroni - SISSA & DEMOCRITOS National Simulation Center - Trieste http://stefano.baroni.me [+39] 040 3787 406 (tel) -528 (fax) / stefanobaroni (skype) La morale est une logique de l'action comme la logique est une morale de la pens?e - Jean Piaget -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20120603/1e280bb9/attachment.htm
[Pw_forum] about the electron-phonon coefficients
Dear all, Greetings! I have a simple question. In the appendix of the user guide (http://www.quantum-espresso.org/wp-content/uploads/Doc/ph_user_guide/node12.html), the electron-phonon coefficient has a factor (1/M)^0.5. This is calculated in the ph.x program. Is the M the total mass of the unit cell, or reduced mass, or averaged mass? Thanks very much. regards, Xiaodong Li North Carolina State University, NC, US -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20120603/670b69f7/attachment.htm
[Pw_forum] Finite Temperature Schrödinger Equation.
I haven't found any efficiency and powerful method to solve Schrodinger Equ with temperature effect. But the paper you mentioned, was published in "International Journal of Theoretical Physics", which is an open access journal with IF=0.67. I briefly read that paper, but I do not think one can directly use such a method into practicing and I am also afraid there r some problems in the equations. If you really wanna obtain some properties (ex. band info) from DFT, the semi-emperical AHC method or DFPT method may give you some help. -- GAO Zhe CMC Lab, Materials Science & Engineering Department, Seoul National University, South Korea ? 2012-06-02 22:24:40?"Hongsheng Zhao" ??? >Hi all, > >I've learned that the "Finite Temperature Schr?dinger Equation" from here: > >http://arxiv.org/abs/1005.2751 > >Basically, I've two issues on the above paper: > >1- Does someone has any hints on how to realize it in pwscf? > >2- Besides this method, are there other methods for taking the >temperature into effect within Schr?dinger Equation? Which is the most >feasible schedule till now? > >Regards >-- >Hongsheng Zhao >School of Physics and Electrical Information Science, >Ningxia University, Yinchuan 750021, China >___ >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/20120603/8dc04d33/attachment.htm
