On Thu, Feb 4, 2010 at 4:18 PM, <pw_forum-request at pwscf.org> wrote:
> Send Pw_forum mailing list submissions to > pw_forum at pwscf.org > > To subscribe or unsubscribe via the World Wide Web, visit > http://www.democritos.it/mailman/listinfo/pw_forum > or, via email, send a message with subject or body 'help' to > pw_forum-request at pwscf.org > > You can reach the person managing the list at > pw_forum-owner at pwscf.org > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of Pw_forum digest..." > > > Today's Topics: > > 1. Re: Kponts generation from kpoint.x (vtmtrinh at caltech.edu) > 2. Re: Kponts generation from kpoint.x (Paolo Giannozzi) > 3. Re: Kponts generation from kpoint.x (Gabriele Sclauzero) > 4. Re: how to conver to unit of eV/atom in supercell? > (Gabriele Sclauzero) > 5. Re: Kponts generation from kpoint.x (Vo, Trinh (388C)) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Wed, 3 Feb 2010 22:49:01 -0800 (PST) > From: vtmtrinh at caltech.edu > Subject: Re: [Pw_forum] Kponts generation from kpoint.x > To: "PWSCF Forum" <pw_forum at pwscf.org> > Message-ID: > <49417.66.215.89.65.1265266141.squirrel at webmail.caltech.edu> > Content-Type: text/plain;charset=iso-8859-1 > > Dear PWSCF Users, > > I also checked prevoius discussions in PWSCF forum. pw.x also takes into > consideration of the crystal symmetry, while kpoint.x uses lattice > symmetry. (My studied system is body-cntered tetragonal cell). It seems > that I could not use the kpoints list given by kpoint.x. If I would like > to obtain a whole list of kpoints (consistent with those generated by > pw.x), how could I do so? > > Thank you, > > Trinh > > > Dear Pwscf, > > > > I run a nscf calculation with k-point grid of 12x12x12 (automatic). From > > the output of pw.x, I saw 163 kpoints were generated and computed. Since > > I would like to get the whole 3D-band structure, I run kpoint.x to get > > other kpoints. A number of kpoints generated by pw.x (for the nscf > > calcultion) could be found te coincide with those generated by kpoint.x. > > However, there many kpoints generated by pw.x could not found in the > > output of kpoint.x. I am not sure about the reason why there is the > > difference here: Is it due to reverse symmetry or something else? I > > appreciate very much if you could tell me why. > > > > Best, > > > > Trinh Vo > > > > JPL/CalTech > > > > > > > > _______________________________________________ > > Pw_forum mailing list > > Pw_forum at pwscf.org > > http://www.democritos.it/mailman/listinfo/pw_forum > > > > > > > ------------------------------ > > Message: 2 > Date: Thu, 4 Feb 2010 08:48:38 +0100 > From: Paolo Giannozzi <giannozz at democritos.it> > Subject: Re: [Pw_forum] Kponts generation from kpoint.x > To: PWSCF Forum <pw_forum at pwscf.org> > Message-ID: <680AB988-245A-47ED-8517-BD239D213990 at democritos.it> > Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed > > > On Feb 4, 2010, at 7:49 , vtmtrinh at caltech.edu wrote: > > > If I would like to obtain a whole list of kpoints (consistent with > > those > > generated by pw.x), how could I do so? > > what do you mean by "a whole list of k-points"? one that covers the > entire > BZ ? there is an option in kpoints.x . You can also use option "nosym" > in pw.x. > > P. > --- > Paolo Giannozzi, Dept of Physics, University of Udine > via delle Scienze 208, 33100 Udine, Italy > Phone +39-0432-558216, fax +39-0432-558222 > > > > > > ------------------------------ > > Message: 3 > Date: Thu, 04 Feb 2010 09:02:45 +0100 > From: Gabriele Sclauzero <sclauzer at sissa.it> > Subject: Re: [Pw_forum] Kponts generation from kpoint.x > To: PWSCF Forum <pw_forum at pwscf.org> > Message-ID: <4B6A7F25.4010806 at sissa.it> > Content-Type: text/plain; charset=us-ascii; format=flowed > > > > vtmtrinh at caltech.edu wrote: > > Dear PWSCF Users, > > > > I also checked prevoius discussions in PWSCF forum. pw.x also takes into > > consideration of the crystal symmetry, while kpoint.x uses lattice > > symmetry. (My studied system is body-cntered tetragonal cell). It seems > > that I could not use the kpoints list given by kpoint.x. If I would > like > > You got the point! > > > to obtain a whole list of kpoints (consistent with those generated by > > pw.x), how could I do so? > > I'm not sure that your request is totally clear to me. If you want the full > list of > k-points, without any symmetry reduction, you can use kpoints.x: it has an > option which > prints on output the full list, together with an index which tells you if > there is in the > list another k-point which is equivalent by symmetry. > I think you could even generate the mesh "by hand" in crystal coordinates: > it is a > regularly spaced grid in a three dimensional cube, possibly shifted from > the origin. > Give a look inside PW/kpoint_grid.f90: > > do i=1,nk1 > do j=1,nk2 > do k=1,nk3 > ! this is nothing but consecutive ordering > n = (k-1) + (j-1)*nk3 + (i-1)*nk2*nk3 + 1 > ! xkg are the components of the complete grid in crystal axis > xkg(1,n) = DBLE(i-1)/nk1 + DBLE(k1)/2/nk1 > xkg(2,n) = DBLE(j-1)/nk2 + DBLE(k2)/2/nk2 > xkg(3,n) = DBLE(k-1)/nk3 + DBLE(k3)/2/nk3 > end do > end do > end do > > However maybe there is no need to do this if you simply want to run a nscf > calculation on > a full 3D grid of k-point; try with > > nosym=.TRUE. > noinv=.TRUE. > > It should disable any symmetry reduction in the generation of the k-point > list (but also > symmetrization of charge). > > > > HTH > > GS > > > > > > > Thank you, > > > > Trinh > > > >> Dear Pwscf, > >> > >> I run a nscf calculation with k-point grid of 12x12x12 (automatic). > From > >> the output of pw.x, I saw 163 kpoints were generated and computed. > Since > >> I would like to get the whole 3D-band structure, I run kpoint.x to get > >> other kpoints. A number of kpoints generated by pw.x (for the nscf > >> calcultion) could be found te coincide with those generated by kpoint.x. > >> However, there many kpoints generated by pw.x could not found in the > >> output of kpoint.x. I am not sure about the reason why there is the > >> difference here: Is it due to reverse symmetry or something else? I > >> appreciate very much if you could tell me why. > >> > >> Best, > >> > >> Trinh Vo > >> > >> JPL/CalTech > >> > >> > >> > >> _______________________________________________ > >> 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 > > > > -- > > > o ------------------------------------------------ o > | Gabriele Sclauzero, PhD Student | > | c/o: SISSA & CNR-INFM Democritos, | > | via Beirut 2-4, 34014 Trieste (Italy) | > | email: sclauzer at sissa.it | > | phone: +39 040 3787 511 | > | skype: gurlonotturno | > o ------------------------------------------------ o > > > ------------------------------ > > Message: 4 > Date: Thu, 04 Feb 2010 09:08:41 +0100 > From: Gabriele Sclauzero <sclauzer at sissa.it> > Subject: Re: [Pw_forum] how to conver to unit of eV/atom in supercell? > To: PWSCF Forum <pw_forum at pwscf.org> > Message-ID: <4B6A8089.9080009 at sissa.it> > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > > > Wong Kelvin wrote: > > Dear all > > > > when i calculate a single atomc Cu primitive cell, the energy is ~ -87 > > What are you trying to compute? An isolated atom or a bulk phase? In any > case, if you are > using pseudopotentials the total energy has not any physical meaning by > itself. What is > physically relevant are energy differences. > > > Ry. How to convert it to the eV/atom which normally is around -3.7 eV? > > Where did you get this value of -3.7 and what does it actually refer to? I > mean, to which > physical quantity? > > > GS > > Thanks > > Wong > > > > > o ------------------------------------------------ o > | Gabriele Sclauzero, PhD Student | > | c/o: SISSA & CNR-INFM Democritos, | > | via Beirut 2-4, 34014 Trieste (Italy) | > | email: sclauzer at sissa.it | > | phone: +39 040 3787 511 | > | skype: gurlonotturno | > o ------------------------------------------------ o > > Dear Gabriele Thanks for reply! I am trying to calculate the grain and twin boundary energies in metals. I partially understand that absolute energy in pseudopotential calculation does not provide meaningful interpretation. The reported energies in literature for copper with PP calculations use to be around -3.7 eV/atom. Is there anything significant abt this figure? and i do not understand how to get it. simple by diving the total energy calculated by number of atom in supercell? if it is so, the value (~3.7) is way too small as compare to the 87 Ry for one copper atom primitive cell. regards Kelvin > ------------------------------ > > Message: 5 > Date: Thu, 4 Feb 2010 00:11:43 -0800 > From: "Vo, Trinh (388C)" <Trinh.Vo at jpl.nasa.gov> > Subject: Re: [Pw_forum] Kponts generation from kpoint.x > To: PWSCF Forum <pw_forum at pwscf.org> > Message-ID: <C78FC13F.128B%Trinh.Vo at jpl.nasa.gov<C78FC13F.128B%25Trinh.Vo > at jpl.nasa.gov> > > > Content-Type: text/plain; charset="us-ascii" > > Hi Paol and Gabriele, > > Thank you very much for reply. > > Yes, I need kpoints for entire BZ. Yes, I used that option (kpoint.x) to > print out all kpoints. I then found that a number of kpoints from pw.x did > not in the list of kpoints generated by kpoint.x, so I was confused. I > have > just made further checks, I saw that they are actually equivalent within a > reciprocal vector. Thus it is fine now. :-). > > Thank you > > > On 2/4/10 12:02 AM, "Gabriele Sclauzero" <sclauzer at sissa.it> wrote: > > > > > > > vtmtrinh at caltech.edu wrote: > >> Dear PWSCF Users, > >> > >> I also checked prevoius discussions in PWSCF forum. pw.x also takes > into > >> consideration of the crystal symmetry, while kpoint.x uses lattice > >> symmetry. (My studied system is body-cntered tetragonal cell). It seems > >> that I could not use the kpoints list given by kpoint.x. If I would > like > > > > You got the point! > > > >> to obtain a whole list of kpoints (consistent with those generated by > >> pw.x), how could I do so? > > > > I'm not sure that your request is totally clear to me. If you want the > full > > list of > > k-points, without any symmetry reduction, you can use kpoints.x: it has > an > > option which > > prints on output the full list, together with an index which tells you if > > there is in the > > list another k-point which is equivalent by symmetry. > > I think you could even generate the mesh "by hand" in crystal > coordinates: it > > is a > > regularly spaced grid in a three dimensional cube, possibly shifted from > the > > origin. > > Give a look inside PW/kpoint_grid.f90: > > > > do i=1,nk1 > > do j=1,nk2 > > do k=1,nk3 > > ! this is nothing but consecutive ordering > > n = (k-1) + (j-1)*nk3 + (i-1)*nk2*nk3 + 1 > > ! xkg are the components of the complete grid in crystal > axis > > xkg(1,n) = DBLE(i-1)/nk1 + DBLE(k1)/2/nk1 > > xkg(2,n) = DBLE(j-1)/nk2 + DBLE(k2)/2/nk2 > > xkg(3,n) = DBLE(k-1)/nk3 + DBLE(k3)/2/nk3 > > end do > > end do > > end do > > > > However maybe there is no need to do this if you simply want to run a > nscf > > calculation on > > a full 3D grid of k-point; try with > > > > nosym=.TRUE. > > noinv=.TRUE. > > > > It should disable any symmetry reduction in the generation of the k-point > list > > (but also > > symmetrization of charge). > > > > > > > > HTH > > > > GS > > > > > > > >> > >> Thank you, > >> > >> Trinh > >> > >>> Dear Pwscf, > >>> > >>> I run a nscf calculation with k-point grid of 12x12x12 (automatic). > From > >>> the output of pw.x, I saw 163 kpoints were generated and computed. > Since > >>> I would like to get the whole 3D-band structure, I run kpoint.x to get > >>> other kpoints. A number of kpoints generated by pw.x (for the nscf > >>> calcultion) could be found te coincide with those generated by > kpoint.x. > >>> However, there many kpoints generated by pw.x could not found in the > >>> output of kpoint.x. I am not sure about the reason why there is the > >>> difference here: Is it due to reverse symmetry or something else? I > >>> appreciate very much if you could tell me why. > >>> > >>> Best, > >>> > >>> Trinh Vo > >>> > >>> JPL/CalTech > >>> > >>> > >>> > >>> _______________________________________________ > >>> 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 > >> > > > > ------------------------------ > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > > > End of Pw_forum Digest, Vol 32, Issue 7 > *************************************** > -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20100204/affaf4bc/attachment-0001.htm
