[Pw_forum] How to control number of slabs in pwcond calculation?
Dear Hui Wang. There is no simple way to control the number of slabs. By default it is equal to nr3s, the number of smooth mesh points in the z direction (direction of transport), as defined in PW and which is controlled by the cut-off energy for pseudo wave functions. Anyway, I do not think there is any reason to change nrz by hands (not by changing the cut-off energy) ... Quoting xirainbow : > Dear all: I find the following content at > "/espresso-4.0.4/examples/example12/results/al.cond.out" file. > *" nrz = 21* > *.* > *k slabz(k) z(k+1) crossing(iorb=1,norb)* > *1 0. 0.0673 0.0673 * > *.* > * 20 1.2793 1.3467 0.0673 0111* > * 21 1.3467 1.4140 0.0673 "* > > I want to know, at *.cond.in input file, how to control the number of > slabs along z direction in left, right lead and scattering region, > respectively. > By the way, what is the meaning of "crossing(iorb=1,norb)"? it is 1 (or 0) if the nonlocal orbital iorb intersects (or not) the corresponding slab. Regards, Alexander > > Thanks in advance :) > > > > Hui Wang > School of physics, Nankai University, Tianjin, China > SISSA Webmail https://webmail.sissa.it/ Powered by Horde http://www.horde.org/
[Pw_forum] tetrahedron method
If a calculation is done using the tetrahedron method, how to get the LDOS and PDOS ? Regards, ?lvaro Santos Alves Universidade Federal Fluminense Niter?i, Rio de Janeiro, Brasil Veja quais s?o os assuntos do momento no Yahoo! +Buscados http://br.maisbuscados.yahoo.com -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20090912/1229c236/attachment.htm
[Pw_forum] occupations from input
dear Lorenzo PaulattoThank you for you clear explanation i understood it now. previously i was not clear how these fractions are coming but now it is clear. Thank you very much for your explanation On Sat, Sep 12, 2009 at 1:45 PM, Lorenzo Paulatto wrote: > > On Sat, September 12, 2009 08:15, udayagiri sai babu wrote: > > Dear all > > Can somebody clearly tell me how to define occupations from input. I > cant > > find much about that in this forum. The card "occupations" described in > > the > > example 11 for Al is not at all clear to me. What are those values mean. > > Looking forward to your help > > > It's quite easy, actually, there are only a couple of points you have to > keep in mind: > > 1. if nspin=1 occupations can go from 0 to 2, you have to specify the > occupation from the lower to the highest band and the sum of the > occupations will have to be the number of electrons; > > 2. if nspin=2 occupations go from 0 to 1, you specify the occupation for > spin up first, then for spin down (always on a newline); > > Let's say you want to reproduce the calculation of the Cr isolated atom, > with semicore states in valence: 3s2 3p6 4s1 3d5 4p0 > > first with nspin=1 and spherical (as it is done in ld1.x): > OCCUPATIONS > 22 2 2 1 1 1 1 1 1 0 0 0 > !3s23p6 4s1 3d54p0 > > then spin polarized (nspin=2), according to Hund's rule you have to > maximize the total angular momentum: > OCCUPATIONS > 11 1 1 1 1 1 1 1 1 0 0 0 > 11 1 1 0 0 0 0 0 0 0 0 0 > !3s23p6 4s1 3d54p0 > > Chrome is a lucky case, as it has a spherical ground state. As a last > example let's take an oxygen atom (2s2 2p4) and set the occupations to > reproduce the ld1.x calculation: > OCCUPATIONS > 2 4/3 4/3 4/3 > > or, equivalently: > OCCUPATIONS > 21.33 1.33 1.34 > > > I hope it helps, best regards > > -- > Lorenzo Paulatto > SISSA & DEMOCRITOS (Trieste) > phone: +39 040 3787 511 > skype: paulatz > www: http://people.sissa.it/~paulatto/<http://people.sissa.it/%7Epaulatto/> > > > > > SISSA Webmail https://webmail.sissa.it/ > Powered by SquirrelMail http://www.squirrelmail.org/ > > ___ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > -- U.Saibabu PhD student, Deformation mechanisms modeling group, Materials engineering department, IISc Bangalore, India. -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20090912/f14a56e7/attachment.htm
[Pw_forum] occupations from input
Dear Xirainbow If i have to write occupations from input for say for Cr (nbnd=12) how does my occupations card look like On Sat, Sep 12, 2009 at 11:59 AM, xirainbow wrote: > Dear udayagiri sai babu? *If you deal with non-metal, you can choose > "fixed".* > In metal, band structure will cross fermi level. This may result into > non-convergence of scf calculation. > *Therefore,if you deal with metal, the occupation can accelerate the > convergence.* > *But you much check the convergence of the occupation value.* > > http://blog.sina.com.cn/s/blog_5f15ead20100d1ki.html > There are some convergence test result. I hope it will give you some help?? > * > * > On Sat, Sep 12, 2009 at 6:15 AM, udayagiri sai babu gmail.com>wrote: > >> Dear all >> Can somebody clearly tell me how to define occupations from input. I cant >> find much about that in this forum. The card "occupations" described in the >> example 11 for Al is not at all clear to me. What are those values mean. >> Looking forward to your help >> >> >> -- >> U.Saibabu >> PhD student, >> Deformation mechanisms modeling group, >> Materials engineering department, >> IISc Bangalore, >> India. >> >> >> ___ >> Pw_forum mailing list >> Pw_forum at pwscf.org >> http://www.democritos.it/mailman/listinfo/pw_forum >> >> > > > -- > > Hui Wang > School of physics, Nankai University, Tianjin, China > > ___ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > > -- U.Saibabu PhD student, Deformation mechanisms modeling group, Materials engineering department, IISc Bangalore, India. -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20090912/28dfa5c7/attachment.htm
[Pw_forum] occupations from input
Dear all Can somebody clearly tell me how to define occupations from input. I cant find much about that in this forum. The card "occupations" described in the example 11 for Al is not at all clear to me. What are those values mean. Looking forward to your help -- U.Saibabu PhD student, Deformation mechanisms modeling group, Materials engineering department, IISc Bangalore, India. -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20090912/c83c7222/attachment.htm
[Pw_forum] occupations from input
On Sat, September 12, 2009 08:15, udayagiri sai babu wrote: > Dear all > Can somebody clearly tell me how to define occupations from input. I cant > find much about that in this forum. The card "occupations" described in > the > example 11 for Al is not at all clear to me. What are those values mean. > Looking forward to your help It's quite easy, actually, there are only a couple of points you have to keep in mind: 1. if nspin=1 occupations can go from 0 to 2, you have to specify the occupation from the lower to the highest band and the sum of the occupations will have to be the number of electrons; 2. if nspin=2 occupations go from 0 to 1, you specify the occupation for spin up first, then for spin down (always on a newline); Let's say you want to reproduce the calculation of the Cr isolated atom, with semicore states in valence: 3s2 3p6 4s1 3d5 4p0 first with nspin=1 and spherical (as it is done in ld1.x): OCCUPATIONS 22 2 2 1 1 1 1 1 1 0 0 0 !3s23p6 4s1 3d54p0 then spin polarized (nspin=2), according to Hund's rule you have to maximize the total angular momentum: OCCUPATIONS 11 1 1 1 1 1 1 1 1 0 0 0 11 1 1 0 0 0 0 0 0 0 0 0 !3s23p6 4s1 3d54p0 Chrome is a lucky case, as it has a spherical ground state. As a last example let's take an oxygen atom (2s2 2p4) and set the occupations to reproduce the ld1.x calculation: OCCUPATIONS 2 4/3 4/3 4/3 or, equivalently: OCCUPATIONS 21.33 1.33 1.34 I hope it helps, best regards -- Lorenzo Paulatto SISSA & DEMOCRITOS (Trieste) phone: +39 040 3787 511 skype: paulatz www: http://people.sissa.it/~paulatto/ SISSA Webmail https://webmail.sissa.it/ Powered by SquirrelMail http://www.squirrelmail.org/
[Pw_forum] occupations from input
Dear udayagiri sai babu?*Sorry, I am not fully understand what you want??* *You can find how to set occupation at example directory.* For example: occupation = 'smearing' smearing = 'gaussian' degauss=0.001 / Or you can use PWgui for convenience?? On Sat, Sep 12, 2009 at 6:52 AM, udayagiri sai babu wrote: > Dear Xirainbow > If i have to write occupations from input for say for Cr (nbnd=12) how does > my occupations card look like > Hui Wang School of physics, Nankai University, Tianjin, China -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20090912/c7b89c14/attachment.htm
[Pw_forum] occupations from input
Dear udayagiri sai babu? *If you deal with non-metal, you can choose "fixed".* In metal, band structure will cross fermi level. This may result into non-convergence of scf calculation. *Therefore,if you deal with metal, the occupation can accelerate the convergence.* *But you much check the convergence of the occupation value.* http://blog.sina.com.cn/s/blog_5f15ead20100d1ki.html There are some convergence test result. I hope it will give you some help?? * * On Sat, Sep 12, 2009 at 6:15 AM, udayagiri sai babu wrote: > Dear all > Can somebody clearly tell me how to define occupations from input. I cant > find much about that in this forum. The card "occupations" described in the > example 11 for Al is not at all clear to me. What are those values mean. > Looking forward to your help > > > -- > U.Saibabu > PhD student, > Deformation mechanisms modeling group, > Materials engineering department, > IISc Bangalore, > India. > > > ___ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > > -- Hui Wang School of physics, Nankai University, Tianjin, China -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20090912/b1f44092/attachment.htm
[Pw_forum] How to control number of slabs in pwcond calculation？
Dear* *Manoj Srivastava: * Thanks very much for your reply ??* * As I am not familiar with fortran, it is not a good idea for me to change the script ??* * I collect the distance between neighboring slabs?* * 4.57*0.0566=0.259 (ni.cond.out) 12*0.025=0.3 (Alwireal.cond.out) 5.3*0.0673=0.357 (al.cond.out) 12*0.025=0.3(for lead) 12*0.0257=0.308(for scattering) (AlwireH.cond.out) I think the default value for neighboring-slab distance is around 0.3 a.u. Thanks again ?? * Hui Wang School of physics, Nankai University, Tianjin, China -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20090912/a1f53635/attachment.htm
[Pw_forum] K Points and Band structures
And also Dear, recently, Summer school on *Materials modeling from first principles: theory and practice*, ICMR, University of California at Santa Barbara, July 19-31, 2009 was held for Quantum Espresso, and the slides and video lectures are given at link http://www.quantum-espresso.org/wiki/index.php/QESB09 My advise is that please have a look on the slides, as they are very useful. Take Care. On Fri, Sep 11, 2009 at 5:15 PM, Shaptrishi Sharma wrote: > Hi QEs users, > > Can anybody please help me in understanding what are the k points ?? I have > read books a lot but its difficult to understand. > > And also how do we choose k points while performing a band structure > calculation in quantum espresso when we are having 330 atoms. > > Thanks > > S > > ___ > 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/20090912/539f7cd6/attachment.htm
[Pw_forum] K Points and Band structures
Dear Shaptrishi Sharma, I am also a student like you and what i have understood, what is K points, is as follows. We know that charge density is given by ?(r) = ?i=1 Ne/2 |?i(r)|2 with the Bloch theorem we can write as ?= ?n=1 Ne/cell ? d3k|?kn(r)|2 but since the integration is a continuous quantity, we choose the K point mesh in the Brillouin Zone and we have ?= ?n=1 Nb (2?)3/V ? (k ? mesh in BZ) d3k|?kn(r)|2 Where ?kn(r)= eik.r ?(G=reciprocal Lattice vector) Ckn[eiG.r/V(1/2)] And the term in bracket is the plane wave basis and for visualization, what u can do, make any structure, open with Xcrysden ,and go to tools --> K-path selection, there the BZ of your structure will be displayed, with some high symmetry K points (dots). Dear Shaptrishi Sharma, also a lot of times they have asked you to provide your full affilation. Please Do it. To all my guides, in the forum, I may be wrong at any point above, if so please correct me as my group is totally experimental and its my own understanding. Dev Sharma, University of Delhi On Fri, Sep 11, 2009 at 5:29 PM, Stefano de Gironcoli wrote: > Shaptrishi Sharma wrote: > > Hi QEs users, > > > > Can anybody please help me in understanding what are the k points ?? I > > have read books a lot but its difficult to understand. > Please ask to any solid state physicist nearby. > > > And also how do we choose k points while performing a band structure > > calculation in quantum espresso when we are having 330 atoms. > If you still have QE specific doubts after you have understood Bloch > theorem, Real and Reciprocal Space lattices, Brilloun Zone and the like > please formulate them again, trying to be specific. > > Thanks > > S > Please provide your affilaition. > > Best regards, > > Stefano de Gironcoli - SISSA and DEMOCRITOS > > > > > > > ___ > > 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/20090912/35361561/attachment-0001.htm
