[Pw_forum] calculation of lattice parameter and angle of rhombohedral structure
the three basis vectors of rhombohedral are (after relaxation) : a = ( 0.636439417 -0.367448469 0.640642896 ) b = ( 0.0 0.734896938 0.640642896 ) c = ( -0.636439417 -0.367448469 0.640642896 ) then the lattice paremeter should be: A = sqrt (a1^2+a2^2+a3^2) * alat = 8.05092296 a.u. . The angle between two vectors can be calculated by: cosA = a (*) b / |a (*) b|, where a and b are basis vectors, (*) represents the dot product. -- GAO Zhe CMC Lab, MSE, SNU, Seoul, S.Korea At 2011-11-16 20:14:38,"yedu kondalu" wrote: Dear users, I did the optimization for a compound using variable cell approximation using PWSCF, which belongs to the space group R3m(160) Rhombohedral representation. The primitive vectors in terms of lattice parameter a = 8.25791360 a.u. a(1) = ( 0.619505 -0.357671 0.698774 ) a(2) = ( 0.00 0.715343 0.698774 ) a(3) = ( -0.619505 -0.357671 0.698774 ) after completion of optimization step, the primitive vectors CELL_PARAMETERS (alat= 8.25791360) 0.636439417 -0.367448469 0.640642896 0.0 0.734896938 0.640642896 -0.636439417 -0.367448469 0.640642896 can u please explain me how can I calculate the lattice parameter a and the angle (alpha) ??? Thanks in advance Regards Yedukondalu -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/2016/bd9126e6/attachment.htm
[Pw_forum] calculation of lattice parameter and angle of rhombohedral structure
Dear users, I did the optimization for a compound using variable cell approximation using PWSCF, which belongs to the space group R3m(160) Rhombohedral representation. The primitive vectors in terms of lattice parameter a = 8.25791360 a.u. a(1) = ( 0.619505 -0.357671 0.698774 ) a(2) = ( 0.00 0.715343 0.698774 ) a(3) = ( -0.619505 -0.357671 0.698774 ) after completion of optimization step, the primitive vectors CELL_PARAMETERS (alat= 8.25791360) 0.636439417 -0.367448469 0.640642896 0.0 0.734896938 0.640642896 -0.636439417 -0.367448469 0.640642896 can u please explain me how can I calculate the lattice parameter *a* and the *angle (alpha)* ??? Thanks in advance Regards Yedukondalu -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/2016/3c4493a9/attachment.htm
[Pw_forum] help on atomic position
Dear Adetunji, these are some information, you should use google, is a useful tool http://jap.aip.org/resource/1/japiau/v102/i5/p053704_s1 http://cst-www.nrl.navy.mil/lattice/struk/d5_c.html Best. PhD. std Arles V. Gil Rebaza La Plata - Argentine 2011/11/16 bamidele ibrahim > Dear all, > I am working on Li15Si4 compound and i could not get the correct atomic > positions for each of the > elements in this compound. I will be delighted if anybody can give me the > atomic positions for this compound. > > Adetunji Bamidele Ibrahim > Department of physics,University of Agriculture, > Abeokuta, Ogun State,Nigeria. > > ___ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > > -- ###-> Arles V. <-### -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/2016/dc517002/attachment.htm
[Pw_forum] relax calculation for some atoms in the structure
Dear QE users, I'd like to do a relax calculation for only certain atoms in my structrure while keeping some other ones fixed, but I have not been able to find out how to do so. Would you give me some suggestions? anything would be appreciated. Regards, Tram Bui M.S. Materials Science & Engineering trambui at u.boisestate.edu -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20111116/d3efdf73/attachment.htm
[Pw_forum] 'wf_collect' question
Hello everyone, When setting startingwfc = 'file' the program is supposed to read wfc files from a previous run. But if the previous run uses 'wf_collect' = .ture. the wfc are deleted after scf and converted to evc.dat files at each k point and can not be used as startingwfc. It is really confusing to me that wf_collect does the opposite of what it is supposed to do. Is there any reason behind it? Thanks! Lai Jiang * Department of Chemistry School of Arts and Sciences University of Pennsylvania * 231 South 34th Street, Box 46 Philadelphia, PA 19104 Tel: 215-573-4241 Fax: 215-573-2112 Email: jianglai at sas.upenn.edu -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/2016/4930c8f4/attachment.htm
[Pw_forum] parallel computing for phonon calculations
Dear all, I am doing phonon calculations for a 60 Carbon atom Grain boundary system and I have got in total 180 irreducible representations which in fact take a lot of time and memory (this is if it was completed). Is it efficient to use parallel computing in QE for doing the phonon calculations? Any information on this is highly appreciated.. Thanks Elie MoujaesUniversity of nottinghamNG7 2RDUK -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/2016/c22e82ff/attachment-0001.htm
[Pw_forum] Davidson diagonalization with overlap
Dear Cao The link refers to a prehistoric version of pw and seems to have nothing to do with your problem... I cannot say more without looking at your input file. Giuseppe On Tuesday 15 November 2011 15:24:24 Cao TF wrote: > Dear Giuseppe Mattioli > Thank you very much for your kind replay . When I relax the > structure, the calculation process stops here iteration # 4 ecut= > 30.00 Ry beta=0.70 Davidson diagonalization with overlap. And I google > it and have found this > http://www.democritos.it/pipermail/pw_forum/2003-June/000374.html. I can > not fully understand it, so it appears to me that there in a problem in my > calculation. -- - Article premier - Les hommes naissent et demeurent libres et ?gaux en droits. Les distinctions sociales ne peuvent ?tre fond?es que sur l'utilit? commune - Article 2 - Le but de toute association politique est la conservation des droits naturels et imprescriptibles de l'homme. Ces droits sont la libert?, la propri?t?, la s?ret? et la r?sistance ? l'oppression. ? ?Giuseppe Mattioli ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?CNR - ISTITUTO DI STRUTTURA DELLA MATERIA ? ? ?v. Salaria Km 29,300 - C.P. 10 ? ? ? ? ? ? ? ? ? ?I 00015 - Monterotondo Stazione (RM) ? ? ? ? ? ? ?Tel + 39 06 90672836 - Fax +39 06 90672316 ? ? ? ?E-mail:
[Pw_forum] QHA frequency is higher than *.freq
Repeating an ill-formulated question is unlikely to attract answers -- Paolo Giannozzi, IOM-Democritos and University of Udine, Italy
[Pw_forum] Problem with DFT + U calculations
On Sun, 2011-11-13 at 23:31 -0500, Lai Jiang wrote: > I'm having some problem getting convergence in my DFT +U calculations. there are two different problems here: Bad convergence is one, and it is unfortunately a quite common problem with DFT+U. I offer no suggestions for this, except the following: the smearing (degauss) seems to me rather small, and this could lead to socillations and instabilities. The crash is a different problem, which may or may not be related to bad convergence. Unless a case is found for which the error can be reproduced (again: in a reasonable time, on a resonable machine), it is hard to say anything about it P. -- Paolo Giannozzi, IOM-Democritos and University of Udine, Italy
[Pw_forum] QHA frequency is higher than *.freq
Yun Song,Kang Department Physical Science and Technology of Inner Mongolia University. From: songsong19840...@hotmail.com To: pw_forum at pwscf.org Date: Sun, 13 Nov 2011 11:18:45 + Subject: Re: [Pw_forum] QHA frequency is higher than *.freq Yun Song,Kang Department Physical Science and Technology of Inner Mongolia University. From: songsong19840...@hotmail.com To: pw_forum at pwscf.org Date: Fri, 11 Nov 2011 12:55:14 + Subject: Re: [Pw_forum] QHA frequency is higher than *.freq Hi, The pdos is not similar to phonon dispersion and the frequency is not negative from ph.x. Yun Song,Kang Department Physical Science and Technology of Inner Mongolia University. From: songsong19840...@hotmail.com To: pw_forum at pwscf.org Date: Thu, 10 Nov 2011 12:15:50 + Subject: [Pw_forum] QHA frequency is higher than *.freq Hi, Recently,I calculated the phonon dispersion.And I use the *.fc from matdyn q2r.x to calculate frequecy and pdos.But this is a problem the freqency from matdyn.x of QHA is higher than *.freq from matdyn.x of phonon dispersion calculation.Why?Could anyone help me?The other material I use this method did not meet this problem. The matdyn.in of QHA is: amass(1)=*, amass(2)=*, asr='crystal', flfrc=*.fc, flfrq='frequency' 1183 -0.3 0.57735 0.81850 1.0 -0.30555 0.52924 0.75029 1.0 -0.30555 0.57735 0.75029 1.0 ?? The matdyn.in of phonon dispersion calculating is : asr='simple', amass(1)=*, amass(2)=*, flfrc='*.fc', flfrq='*.freq' ,la2F=.false. , / 85 0.000 0.000 0.3092146, wk = 0.0235294 0.060 0.000 0.3092146, wk = 0.0235294 0.110 -0.006 0.3092146, wk = 0.0235294 0.170 0.006 0.3092146, wk = 0.0235294 0.220 0.000 0.3092146, wk = 0.0235294 0.280 0.000 0.3092146, wk = 0.0235294 Yun Song,Kang Department Physical Science and Technology of Inner Mongolia University. ___ 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 -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/2016/29cdc1e3/attachment.htm
[Pw_forum] Obtaining SCF convergence for Relax Calculation
1 H7.4241095089.2032374295.274512036 1 1 1 H5.1003370245.8226594593.767507361 1 1 1 H6.517771718 10.8314455680.753510895 1 1 1 H8.841713653 14.2121661552.260519512 1 1 1 H7.422992747 19.2207526552.260508677 1 1 1 H5.099584539 15.8400881280.753466022 1 1 1 H6.517839937 10.8314559163.767489843 1 1 1 H8.841869110 14.2120736475.274479452 1 1 1 H7.423237889 19.2208274465.274488671 1 1 1 H5.099503033 15.8401183783.767533284 1 1 1 K_POINTS automatic 4 6 4 0 0 0 -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/2016/61514765/attachment-0001.htm -- next part -- A non-text attachment was scrubbed... Name: GRLXBLYP3512x.in.log Type: application/octet-stream Size: 39874 bytes Desc: not available Url : http://www.democritos.it/pipermail/pw_forum/attachments/2016/61514765/attachment-0001.obj
[Pw_forum] atomic position of Li15Si4
Dear all, please I need assistance from anybody in the forum who have an idea on how to get atomic position of Li15Si4 compound. -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/2016/663e5cd6/attachment.htm
[Pw_forum] help on atomic position
Dear all, ? I am working on Li15Si4 compound and i could not get the correct atomic positions for each of the elements in this compound. I will be delighted if anybody can give me the atomic positions for this compound. ? Adetunji Bamidele Ibrahim Department of physics,University of Agriculture, Abeokuta, Ogun State,Nigeria. -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/2016/6e8d12b9/attachment.htm
