[Pw_forum] Raman spectra calculatio using QE
Dear All, Is there anyone have done Raman spectra using QE? I tried to run the SiH4 example which could be downloaded from the QE website. The process i did is very simple, after scf calculation using the defalt sih4.scf.in file, i ran the sih4.nm.in file using ph.x. But i got an error as " cannot start from pw.x data file using Gamma-point tricks". So what's wrong with my calculation? Thanks for any help! Best regards, Min WU -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20111027/37850f5b/attachment.htm
[Pw_forum] Raman spectra calculatio using QE
Thanks. I ran sih4.scf.in and sih4.nm.in and got the output files. But how can i get the Raman spectra from the output file? Where is the Raman intensity? Min Wu >From: "GAO Zhe" >Reply-To: PWSCF Forum >To: "PWSCF Forum" >Subject: Re: [Pw_forum] Raman spectra calculatio using QE >Date: Thu, 27 Oct 2011 14:29:20 +0800 (CST) > If you are using K_POINTS gamma in scf but still wanna use ph.x for further calculaiton, why not try changing K_POINTS gamma to: K_POINTS 1 0.0 0.0 0.0 Or, you can using phcg.x as the follower of K_POINTS gamma case. -- GAO Zhe CMC Lab, MSE, SNU, Seoul, S.Korea At 2011-10-27 04:36:00,wumindt2 wrote: Dear All, Is there anyone have done Raman spectra using QE? I tried to run the SiH4 example which could be downloaded from the QE website. The process i did is very simple, after scf calculation using the defalt sih4.scf.in file, i ran the sih4.nm.in file using ph.x. But i got an error as " cannot start from pw.x data file using Gamma-point tricks". So what's wrong with my calculation? Thanks for any help! Best regards, Min WU ! -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20111028/25ddf165/attachment.htm
[Pw_forum] Raman spectra calculation using QE
Dear All, I calculated the Raman intensity of quartz and got the result shown below. To plot the Raman spectra, colume [cm-1] should be the x axis, is colume [Raman] exactly the y axis? And what's the meaning of the [depol] colume? By the way, since epsil can only be calculated at q=0, does it mean there is no convergence test of Raman spectra with respect to q point? Thanks for any help! " IR cross sections are in (D/A)^2/amu units Raman cross sections are in A^4/amu units multiply Raman by 0.435857 for Clausius-Mossotti correction # mode [cm-1] [THz] IR Raman depol 1 0.000.0.117648.24780.0796 2 0.000.0. 54851.87790.0878 3 0.000.0. 5721.38990.1088 4 0.000.0. 27197.63830.0792 5 0.000.0.147366.77430.0728 6 0.000.0. 79591.10520.0839 7134.344.02730.0005 11088.31620.6209 8240.107.19810.1622 16185.77660.1558 9241.217.23130.2024 24875.87730.1058 10314.539.42933.0075 5175.33550.2916 11328.759.85570.1138 17701.21400.6847 12346.33 10.38273.1900 13146.61410.1307 13390.34 11.70200.1564 53220.00700.0658 14405.27 12.14969.5614 5754.01260.2673 15434.56 13.02775.7052303619.78840.0609 16470.12 14.09385.8666 2135.04500.5859 17551.14 16.52275.7194 5307.84460.7482 18663.69 19.89692.9906 11422.03260.7170 19664.81 19.93040.5153 14523.92400.4764 20679.62 20.3742 16.2637 2261.00760.2333 21745.02 22.33518.9307157046.73560.1277 22835.16 25.0373 11.9576 5478.45320.6700 23924.96 27.7294 18.0245 18670.74830.2741 24985.40 29.5415 40.4317 10913.62350.3922 25996.49 29.8738 20.1984 46086.85530.5930 26 1052.71 31.5592 13.6824 14469.33200.4908 27 1069.38 32.05910.0030 39309.33120.7484 Min WU University of Saskachewan, Cananda
[Pw_forum] dos calculation
Dear All, I meet a problem with the Dos calculation using projwfc.x. Due to the limit of the disk quota, i need to store the wf files to other directory. So i set the 'outdir' and 'wfcdir' with two different directories. In the discription of projwfc.x, it said that wavefunciton files are needed to calculate the DOS. Since i didn't collect the wavefunctions, the wavefunction files and the *.save file are in two different directory. To do the dos calculation, i set the 'outdir' as the directory of wavefunctions. But then i got an error saying that the *.save file was not found. Does it mean that the 'outdir' and 'wfcdir' should have the same directories? Or otherwise i need to collect the wavefunctions to the *.save file ? Looking forward to your reply. Thanks so much! Min Wu -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20110429/4c161836/attachment.htm
[Pw_forum] pseudopotential
Dear All, I met some problem when printing the stress using different pseudopotentials. The structure i calculated is CO2 solid structure. Using the same structure, when the pseudopotentials are C.pbe-rrkjus.UPF and O.pbe-rrkjus.UPF, the stress tensor i got is entering subroutine stress ... total stress (Ry/bohr**3) (kbar) P= 175.92 0.00114704 0. 0.168.74 0.00 0.00 0. 0.00121085 0.0007 0.00178.12 0.01 0. 0.0007 0.00122973 0.00 0.01180.90 However, when i changed the pseudopotential to C.pbe-mt_gipaw.UPF and O.pbe-van_gipaw.UPF , the stress tensot i got is entering subroutine stress ... total stress (Ry/bohr**3) (kbar) P= 252.11 0.00113269 0. 0.166.62 0.00 0.00 0. 0.00225526 0.0002 0.00331.76 0.00 0. 0.0002 0.00175342 0.00 0.00257.94 Why we will get so much different stress using the different pseudopotential ? The structures i ued are exact same. Thanks for any help. With kind regards, Min Wu 2010-11-5 -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20101106/907af28f/attachment.htm
[Pw_forum] pseudopotential
Dear Paolo, I know the difference, and have already used different cutoff for norm-conserving PP adn ultrasoft PP. Best regards, Min Wu, 2010-11-5 >From: Paolo Giannozzi >Reply-To: >To: wumindt2 ,PWSCF Forum >Subject: Re: [Pw_forum] pseudopotential >Date: Fri, 5 Nov 2010 23:10:15 +0100 > > >On Nov 5, 2010, at 22:02 , wumindt2 wrote: > >> C.pbe-rrkjus.UPF and O.pbe-rrkjus.UPF > >ultrasoft > >> C.pbe-mt_gipaw.UPF and O.pbe-van_gipaw.UPF > >norm-conserving, and quite hard. A cutoff that is appropriate for the >former may ot be sufficient for the latter. This is the first thing >to be >verified. > >P. >--- >Paolo Giannozzi, Dept of Chemistry&Physics, Univ. Udine >via delle Scienze 208, 33100 Udine, Italy >Phone +39-0432-558216, fax +39-0432-558222 > > > > >
[Pw_forum] wannier function
Dear All QE user, I want to plot the localized wannier function of SiO2. In the QE user's guide, there are three wannier-related utilities. 1. "poor man wannier" code pmw.x. Is this only used in LDA+U calculation ? Besides, there isn't any discription of the parameters of this code. 2. Wannier90 code. 3. wannier_ham.x code. So which one is recommended ? Thanks for any help. With regards. Min Wu 2010-11-17 -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20101118/6b4007fb/attachment.htm
[Pw_forum] wannier function
Dearl All, To incorporate wannier90 into PWSCF-4.2.1, do we need to copy pw2wannier90.f90 and wannier.f90 from wannier90 to PWSCF directory, and recompile the PWSCF, or just compile PWSCF and wannier90 individually? Thanks for any help. With Best regards, Min Wu 2010-11-22 -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20101123/966e7635/attachment.htm
[Pw_forum] wannier function
Thanks. BTW, can wannier90.x run with MPI support? And can it plot the wannier function of supercell structure with a defect? Cheers, Min Wu 2010-11-22 >From: Jan Felix Binder >Reply-To: >To: wumindt2 , PWSCF Forum >Subject: Re: [Pw_forum] wannier function >Date: Tue, 23 Nov 2010 09:54:03 +0100 > >You should compile it individually. But you should use the same compiler. > > > >wumindt2 wrote: >> Dearl All, >> >> To incorporate wannier90 into PWSCF-4.2.1, do we need to copy >> pw2wannier90.f90 and wannier.f90 >> from wannier90 to PWSCF directory, and recompile the PWSCF, or just >> compile PWSCF and wannier90 individually? >> >> Thanks for any help. >> >> With Best regards, >> >> Min Wu >> 2010-11-22 >> >> >> ___ >> Pw_forum mailing list >> Pw_forum at pwscf.org >> http://www.democritos.it/mailman/listinfo/pw_forum >> > >
[Pw_forum] wannier function
Dear All, I have a problem using the wannier90.x. Does the wannier90.x can plot the wannier function above the fermi level, i.e. the unocuppied charge density? Thanks! Min Wu 2010-11-25 -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20101126/8a6a419e/attachment.htm
[Pw_forum] wannier function
Hi Stefano, I want to plot the unoccupied state in an energy window, so it can be finite. Because i'm calculating the X-ray absorbtion spectra of SiO2. This is the reason i need the wannier function plotted in an energy window above the Fermi level. Cheers, Wu Min 2010-11-25 >From: Stefano Baroni >Reply-To: >To: wumindt2 ,PWSCF Forum >Subject: Re: [Pw_forum] wannier function >Date: Fri, 26 Nov 2010 08:18:48 +0530 > Not sure i understand what you mean, but the "unoccupied charge density" (i.e. the sum of the squared moduli of the unoccupied orbitals is infinite, for whatever reason you may need it). Or you rather mean the squared modulus of a specific Wannier function obtained from specific energy bands above the Fermi energy? SB On Nov 26, 2010, at 5:35 AM, wumindt2 wrote: Dear All, I have a problem using the wannier90.x. Does the wannier90.x can plot the wannier function above the fermi level, i.e. the unocuppied charge density? Thanks! Min Wu 2010-11-25 ___ 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 Please, if possible, don't send me MS Word or PowerPoint attachments Why? See: http://www.gnu.org/philosophy/no-word-attachments.html -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20101126/cd9e1b32/attachment.htm
[Pw_forum] wannier function
Dearl all, I met an error when i try to calculate the wannier function of Si. The error is "Exiting... param_get_projection: too many projections defined". What's the reason of this error? The input wannier.win file is shown below: "num_bands= 12 num_iter = 100 dis_num_iter = 100 iprint =2 num_dump_cycles = 10 num_print_cycles = 10 length_unit = bohr num_wann= 4 dis_froz_max= 6.5 dis_win_max = 6.5 !! !! Bond-centred s-orbitals begin projections Si:sp3 end projections begin unit_cell_cart bohr -5.10 0.00 5.10 0.00 5.10 5.10 -5.10 5.10 0.00 end unit_cell_cart begin atoms_frac Si -0.25 0.75 -0.25 Si 0.00 0.00 0.00 end atoms_frac mp_grid = 4 4 4 begin kpoints " In the wannier user-guide, there are several options for the defination of the projection. Such as "Si:l=0;l=1;l=2" , " Si: sp3", or "f=-0.125,-0.125, 0.375:s". So how to choose these different options? Thanks for any help. Min Wu 2010-11-29 -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20101130/b24b43ee/attachment.htm
[Pw_forum] wannier function
Dear All, I met an error when calculate the wannier function with wannier90.x. The error is " Wannier90: Execution started on 29Dec2010 at 10:22:40 Exiting... param_get_projection: Problem reading m state into string " What's the meaning of this error? Below is part of my wannier input: "num_bands= 600 num_iter = 100 dis_num_iter = 100 iprint =2 num_dump_cycles = 10 num_print_cycles = 10 !! (1) Valence bands num_wann= 3 dis_froz_min= 17.14 dis_froz_max= 18.14 dis_win_min = 16.95 dis_win_max = 18.95 !! !! Bond-centred s-orbitals begin projections f=0.2985,0.2985,0.4375:p, f=0.2985,0.2985,0.5625:p, f=0.4235,0.4235,0.5000:p, end projections begin unit_cell_cart ang 8.3544 0.00 0.00 0.00 8.3544 0.00 0.00 0.0010.6604 end unit_cell_cart " Happy New Year! Min Wu 2010-1-3 -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20110104/cc54eb70/attachment.htm
[Pw_forum] wannier function
Dear All, I'm a rookie on wannier90, and now I met a problem when i tried to test the example of Si. In the cell of Si, there are 2 inequivalent Si atoms. But in the wannier function plot with two different projections, the wannier function only located on one of the Si atoms. In the users-guide of wannier function, it said the wannier function will apply to all the atom of the type specified in the projection site. So why there is no wannier function on the other Si atom? Any idea? The two different prejections are: !! (1) Valence bands num_wann= 4 dis_froz_max= 6.5 dis_win_max = 6.5 !! !! Bond-centred s-orbitals begin projections f=-0.125,-0.125, 0.375:s f= 0.375,-0.125,-0.125:s f=-0.125, 0.375,-0.125:s f=-0.125,-0.125,-0.125:s end projections !! !! (2) Valence + conduction bands num_wann= 8 dis_froz_max= 6.5 dis_win_max = 17.0 !! !! Atom-centred sp3-orbitals begin projections Si:sp3 end projections Thanks for any help. Min Wu 2010-12-2 -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20101203/d49438e7/attachment.htm
[Pw_forum] wannier function
Dear all, I tested the example of wannier90.x and have a problem here. For the Si calculation (example11), we need to include the 4 highest valence bands and the 4 lowest conduction bands to make a sp3 projection on Si atoms. However, in the case of Silane (example07), we only need all the 4 bands to make a sp3 projection on Si atom. Why we need different number of bands to form sp3 projection for these two material? Thanks for any idea. Min Wu 2010-12-9 -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20101210/e5869952/attachment.htm
[Pw_forum] wannier calculation
Dear All, In the seedname.win file of wannier function calculation, the number of K points has to be equal to the product of n1*n2*n3, where n1, n2 and n3 are the component of the mp_grid= n1 n2 n3. However, in the nscf calculation, the number of Kpoints is always smaller than the product of n1*n2*n3. For instance, if the mp_grid = 4*4*4 in the nscf calculation, but we may have only 36 Kpoints. In this case, we can not move on to the wannier calculation. So, in order to do wannier calculation, how to get the number of Kpoints equals to the product of mp_grid n1*n2*n3 ? Thanks for any help. With regards, Min Wu 2010-12-20 -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20101221/a169cc42/attachment.htm
[Pw_forum] wannier function
Dear All, I met a problem with the wannier calculation. Shall the kpoint mesh in the wannier calculation input *.win file be the same with the kpoint mesh in the nscf calculation ? Thanks for any help! Min Wu 2010-12-28 -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20101228/e1845c33/attachment.htm
[Pw_forum] problem with Xspectra
Hi, I'm a new user of Xspectra. In the Xspectra example given in the pwscf code, it calculates the XAS using the pseudopotential without core hole level. In this case, we need to extract the core wavefunction from the GIPAW pseudopotential when we run the xspectra.x. Now there are pseudopotentials with core hole, normally named as *.star1s*.UPF. So here is my question, after the SCF calculation, do we still need to extract the core wavefunction from the peusopotential of the absorbing atom? If the answer is yes, then why we choose the core wavefunction from the pseudopotential as the ground state, rather than the core wavefunction after the SCF calculation? Thanks! Min Wu 2010-10-4 -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20101005/9e5fe0f8/attachment.htm
[Pw_forum] problem with Xspectra
Dear matteo, Thank you very much! I've got the picture now. BTW, in my previous calculation, i mistakenly extract the core wavefunction from the pseudopotential WITH a core hole. But the result seems good when compared with the experiment. Does it happen often? Cheers, Min Wu 2010-10-5 >From: matteo calandra >Reply-To: PWSCF Forum >To: pw_forum at pwscf.org >Subject: Re:[Pw_forum] problem with Xspectra >Date: Tue, 5 Oct 2010 10:49:48 +0200 > >Dear Min Wu, > > the pseudopotentials to be used for the absorbing atom >in Xspectra are those having >the label _gipaw, two examples are: > >Fe.pbe-sp-mt_gipaw.UPF >Fe.star1s-pbe-sp-mt_gipaw.UPF > >The first one has no core-hole and has full gipaw informations >while the second one has core-hole and full gipaw informations. >Gipaw informations mean many things. What you need to know is that >GIPAW informations include the presence of the >all-electron wavefunction for the 1s core state. > >Now when you run a simulation you first need to calculate the charge >density in the presence of a core-hole and thus use pseudo >Fe.star1s-pbe-sp-mt_gipaw.UPF . This is done by a standard pw.x >scf calculation using this pseudo. >In a second step you need to calcuate the Xanes cross >section and this is done by the Xspectra code. > >In the calculation of the matrix element appearing in the >Xanes cross-section (Fermi golden rule) the initial 1s state >IN THE ABSENCE of a core hole is needed. This information is contanined >in the pseudo potential WITHOUT the core hole (Fe.pbe-sp-mt_gipaw.UPF). >Thus you simply extract this wavefunction using the script given with the >Xspectra disribution and you put the name of the file produced by the script >in the input file of the Xspectra program. > >You cannot use the 1s core function with the core hole simply because this is >wrong as the matrix element inthe cross section involves the product >between the initial and final states and the initial state has no core hole. > >M. >> Message: 1 >> Date: Tue, 05 Oct 2010 00:42:50 +0800 >> From: "wumindt2" >> Subject: [Pw_forum] problem with Xspectra >> To: pw_forum at pwscf.org >> Message-ID: >> Content-Type: text/plain; charset="gb2312" >> >> Hi, >> >> I'm a new user of Xspectra. >> >> In the Xspectra example given in the pwscf code, it calculates the >> XAS using the pseudopotential >> without core hole level. In this case, we need to extract the core >> wavefunction from the GIPAW >> pseudopotential when we run the xspectra.x. >> >> Now there are pseudopotentials with core hole, normally named as >> *.star1s*.UPF. So here is >> my question, after the SCF calculation, do we still need to extract >> the core wavefunction from the >> peusopotential of the absorbing atom? >> >> If the answer is yes, then why we choose the core wavefunction from >> the pseudopotential as the ground >> state, rather than the core wavefunction after the SCF calculation? >> >> Thanks! >> >> Min Wu >> 2010-10-4 > > > >This message was sent using IMP, the Internet Messaging Program. > > >___ >Pw_forum mailing list >Pw_forum at pwscf.org >http://www.democritos.it/mailman/listinfo/pw_forum >
[Pw_forum] Xspectra calculation
Dear Xspectra users, I met a problem when calculating the X-ray absorption spectra with the Xspectra code. Concern about the polarization, ?// is the polarization along the c axis, while ?? is the polariztion in the plane. It's easy to define the ?// , since normally (0,0,1) is the direction of c axis. But for ?? polarization, what does "in plane" mean? Are any directions in the a,b plane will cause the same result? For instance, will (1,0,0) ,(0,1,0) or (1,1,0) polarization direction have the same spectra? Thank you very much for any help. Cheers, Min Wu 2010-10-8 -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20101009/5fd9f157/attachment.htm
[Pw_forum] Xspectra calculation
Dear matteo, Thanks. For dichroism compound, do we just need the in-plane and the c-axis polarization vectors? While for trichroism compound, do we need to calculate three different polarization vectors? Am i right? Best regards, Min Wu 2010-10-9 >From: matteo calandra >Reply-To: PWSCF Forum >To: pw_forum at pwscf.org >Subject: Re: [Pw_forum] Xspectra calculation >Date: Sat, 9 Oct 2010 11:30:54 +0200 > >Dear Wumindt2, > > the fact that different polarization directions can be equivalent or not >in a solid depends only on the symmetry of your lattice (thus on the crystal >structure) only. >So the general response to your question is given by the theory of crystal >symmetries. > >M. > > >> -- >> >> Message: 1 >> Date: Sat, 09 Oct 2010 11:11:16 +0800 >> From: "wumindt2" >> Subject: [Pw_forum] Xspectra calculation >> To: pw_forum at pwscf.org >> Message-ID: >> Content-Type: text/plain; charset="gb2312" >> >> Dear Xspectra users, >> >> I met a problem when calculating the X-ray absorption spectra with >> the Xspectra code. >> Concern about the polarization, ?// is the polarization along the c >> axis, while ?? is the polariztion >> in the plane. It's easy to define the ?// , since normally (0,0,1) >> is the direction of c axis. >> But for ?? polarization, what does "in plane" mean? Are any >> directions in the a,b plane >> will cause the same result? For instance, will (1,0,0) ,(0,1,0) or >> (1,1,0) polarization direction >> have the same spectra? >> >> Thank you very much for any help. >> >> Cheers, >> >> Min Wu >> 2010-10-8 >> -- next part -- >> An HTML attachment was scrubbed... >> URL: >> http://www.democritos.it/pipermail/pw_forum/attachments/20101009/5fd9f157/attachment.html >> >> -- >> >> ___ >> Pw_forum mailing list >> Pw_forum at pwscf.org >> http://www.democritos.it/mailman/listinfo/pw_forum >> >> >> End of Pw_forum Digest, Vol 40, Issue 16 >> >> > > > > >This message was sent using IMP, the Internet Messaging Program. > > >___ >Pw_forum mailing list >Pw_forum at pwscf.org >http://www.democritos.it/mailman/listinfo/pw_forum >
[Pw_forum] Xspectra calculation (wumindt2)
Dear Matteo, Thanks for the information, i read the C. Brouder the paper a little bit. I'am still not sure how to choose the polarization vector. For instance, we have a crystal with spacegroup of P42/MNM, point group of 4/mmm. According to the Table in C. Brouder's paper, this is a dichroism compound. Thus, how can we choose the polarization vector when calculating the XAS of this compound? Can you please show me how? Thanks so much! Cheers, Min Wu 2010-10-12 >From: Matteo Calandra >Reply-To: PWSCF Forum >To: pw_forum at pwscf.org >Subject: Re: [Pw_forum] Xspectra calculation (wumindt2) >Date: Mon, 11 Oct 2010 10:08:16 +0200 > >Dear > > I assume you are talking of the dipolar part only. >For the quadrupolar it is substantially more complicate. >The number of independent calculations that you have >to perform to obtain the isotropic cross section (powder) >depends on the point group of the space group >of your crystal. >It is 1 for a cubic or tetraedric crystal, >2 for a uniaxial crystal and it is 3, 4, 6 for a biaxial >(ot trichroic) crystal. >I suggest you read >C. Brouder J. Phys.: Condens. Matter 2 (1990) 701-738 >for more details. > >M. > > >> >> Message: 3 >> Date: Sat, 09 Oct 2010 22:48:53 +0800 >> From: "wumindt2" >> Subject: Re: [Pw_forum] Xspectra calculation >> To: pw_forum at pwscf.org >> Message-ID: >> Content-Type: text/plain;charset="gb2312" >> >> Dear matteo, >> >> Thanks. >> >> For dichroism compound, do we just need the in-plane and the c-axis >> polarization vectors? >> While for trichroism compound, do we need to calculate three different >> polarization vectors? >> Am i right? >> >> Best regards, >> >___ >Pw_forum mailing list >Pw_forum at pwscf.org >http://www.democritos.it/mailman/listinfo/pw_forum >
[Pw_forum] Xspectra calculation (wumindt2)
Dear Matteo, I met some problem when calculating the XASs with the Xspectra. I tested the example of quartz, and got the consistent result with the published work. Then i moved on to test another example of solid CO2, which has an isotropic symmetry according to C. Brouder's paper. But the X-ray absorption spectrum i got was totally wrong. The first sharp peak which is well-known existing in CO2 was not found. We also tested a single CO2 molecule which is still a clear-cut example. The C atom and the two O atoms are all in the Z axis. So the polarization vectors of (0,0,1) and (1,0,0) are enough for this case. However, we still cannot get the right XAS. To make it easier for you to understand my problem, I attached the input files of this calculation. The GIPAW pseudopotentials i used were downloaded from the website of QE. Thanks a lot for the help. Best regards, Min Wu 2010-10-17 >From: Matteo Calandra >Reply-To: PWSCF Forum >To: pw_forum at pwscf.org >Subject: Re: [Pw_forum] Xspectra calculation (wumindt2) >Date: Mon, 11 Oct 2010 10:08:16 +0200 > >Dear > > I assume you are talking of the dipolar part only. >For the quadrupolar it is substantially more complicate. >The number of independent calculations that you have >to perform to obtain the isotropic cross section (powder) >depends on the point group of the space group >of your crystal. >It is 1 for a cubic or tetraedric crystal, >2 for a uniaxial crystal and it is 3, 4, 6 for a biaxial >(ot trichroic) crystal. >I suggest you read >C. Brouder J. Phys.: Condens. Matter 2 (1990) 701-738 >for more details. > >M. > > >> >> Message: 3 >> Date: Sat, 09 Oct 2010 22:48:53 +0800 >> From: "wumindt2" >> Subject: Re: [Pw_forum] Xspectra calculation >> To: pw_forum at pwscf.org >> Message-ID: >> Content-Type: text/plain;charset="gb2312" >> >> Dear matteo, >> >> Thanks. >> >> For dichroism compound, do we just need the in-plane and the c-axis >> polarization vectors? >> While for trichroism compound, do we need to calculate three different >> polarization vectors? >> Am i right? >> >> Best regards, >> >___ >Pw_forum mailing list >Pw_forum at pwscf.org >http://www.democritos.it/mailman/listinfo/pw_forum > -- next part -- An embedded and charset-unspecified text was scrubbed... Name: scf.in Url: http://www.democritos.it/pipermail/pw_forum/attachments/20101018/1834f743/attachment.txt -- next part -- An embedded and charset-unspecified text was scrubbed... Name: CO2-moleculer.xspectra_b.in Url: http://www.democritos.it/pipermail/pw_forum/attachments/20101018/1834f743/attachment.asc -- next part -- An embedded and charset-unspecified text was scrubbed... Name: CO2-moleculer.xspectra_c.in Url: http://www.democritos.it/pipermail/pw_forum/attachments/20101018/1834f743/attachment-0001.txt
[Pw_forum] xspectra calculation (wumindt2)
Dear Matteo, It seems i have found the problem. It's not the problem of the xcoordcrys. I set it as .true. and the polarization vectors are (0,0,1) and (0,1,0). The xray k vector is the default value (1,0,0). BTW, can we use the same vector for polarization and xay k moment? e.g. Both of them are (1,0,0). Is it OK? The problem i found is that i set the "cut_occ_states" = .true. Then it cut all the occupied state that i expected to see. When i reset it to .false., i saw the expected peak. I have another problem, what does the "ef_r" do in the calculation? For instance, i got fermi level of -5 eV with scf calculation. The i set ef_r= -5/13.6 Ry. Then, in the calculated xspectra data, where is the Fermi level? It is ajusted to 0 eV, or still is the -5 eV? Sorry to bother you again. Thanks so much. Cheers, Min Wu 2010-10-18 >From: Matteo Calandra >Reply-To: PWSCF Forum >To: pw_forum at pwscf.org >Subject: Re:[Pw_forum] xspectra calculation (wumindt2) >Date: Mon, 18 Oct 2010 09:35:10 +0200 > >dear Min Wu, > > the attachment do not go through the pw_forum, so I cannot >do much about it. What I can tell you is that we calculate >Co and LiCoO2 and we get a good agreement with experiments. >Maybe you can try to compare with the following paper: > >Juhin et al. Phys. Rev. B 81, 115115 (2010) >http://link.aps.org/doi/10.1103/PhysRevB.81.115115 > >Anyway, from four message what seems to be wrong (assuming the scf >run to be correct) are the unit of the polarization vector >(assuming you're dealing with the dipolar part only and assuming >the peak you're referring to is dipolar). Did you set xcoordcrys to >the proper value (see below)? > >For zhqt concerns CoO2, note that the pre-edge >of CoO2 at the Co K-edge has a quadrupolar part, so if you stick >to the dipolar calculation you want be able to reproduce the pre-edge >peak. Note also that in the case of LiCoO2, which is probably >not so different from yours, DFT fails in the >pre-edge and you have to use DFT+U. > >In particular, remember that if you don't set the variable >xcoordcrys=.false. your xepsilon and xkvec are in reduced coordinates. > From Doc/INPUT_XSPECTRA > >xkvec(1:3)real(DP) >DEFAULT=(1.0,0 >.0,0.0) > coordinates of the x-ray momentum k > > >xepsilon(1:3) real(DP) >DEFAULT=(1.0,0 >.0,0.0) > coordinates of the incident x-ray > polarization vector > >xcoordcryslogical >DEFAULT=.true. > .true. to use crystal coordinates for > k and epsilon > > >Maybe you could try to reproduce our calculation on LiCoO2 so that >you are sure of not having any errors with the input file. >The paper is very detailed so you can compare every step in the calculation. > >All the best, M. > > >Message: 6 > >Date: Mon, 18 Oct 2010 05:03:50 +0800 > >From: "wumindt2" > >Subject: Re: [Pw_forum] Xspectra calculation (wumindt2) > >To: pw_forum at pwscf.org > >Message-ID: > >Content-Type: text/plain; charset="gb2312" > > >Dear Matteo, > > >I met some problem when calculating the XASs with the Xspectra. > >I tested the example of quartz, and got the consistent result with the > >published work. > >Then i moved on to test another example of solid CO2, which has an > >isotropic > >symmetry according to C. Brouder's paper. But the X-ray absorption > >spectrum > >i got was totally wrong. The first sharp peak which is well-known > >existing > >in CO2 was not found. > >We also tested a single CO2 molecule which is still a clear-cut >example. > >The C atom and the two O atoms are all in the Z axis. So the > >polarization vectors > >of (0,0,1) and (1,0,0) are enough for this case. However, we still > >cannot get the > >right XAS. To make it easier for you to understand my problem, I > >attached the input files of this calculation. > >The GIPAW pseudopotentials i used were downloaded from the website of >QE. > > >Thanks a lot for the help. > > >Best regards, > > >Min Wu >___ >Pw_forum mailing list >Pw_forum at pwscf.org >http://www.democritos.it/mailman/listinfo/pw_forum >
[Pw_forum] xspectra calculation
Dear Matteo, So when we just do the dipolar part, we don't need to care about the k vector, right? Besides, in order to compare with an experimental spectrum, is it necessary to cut the occupied state below Fermi energy level within our Xspectra calculation ? In that case, we should set "cut_occ_states" = .true. and "ef_r" equal to the fermi energy we got in the scf calculation. Is it? Best regards, Min Wu 2010-10 >From: Matteo Calandra >Reply-To: PWSCF Forum >To: pw_forum at pwscf.org >Subject: Re: [Pw_forum] xspectra calculation >Date: Tue, 19 Oct 2010 16:28:30 +0200 > >Dear Min Wu, > > > > >It seems i have found the problem. It's not the problem of the > >xcoordcrys. I set it as .true. and the polarization vectors are >(0,0,1) >and > >(0,1,0). The xray k vector is the default value (1,0,0). > >BTW, can we use the same vector for polarization and xay k moment? > >e.g. Both of them are (1,0,0). Is it OK? > >Of course epsilon and k MUST be ortogonal otherwise what you are doing >is meaningless. If you calculate the dipolar part only then >the k-vector is not used and can take any value. > > > > >The problem i found is that i set the "cut_occ_states" = .true. > >Then it cut all the occupied state that i expected to see. > >When i reset it to .false., i saw the expected peak. > > > >Maybe your ef_r is not in the correct units... Of course you put the >Fermi level in the presence of a core-hole, don't you ? > > >I have another problem, what does the "ef_r" do in the calculation? > >For instance, i got fermi level of -5 eV with scf calculation. > >The i set ef_r= -5/13.6 Ry. Then, in the calculated xspectra data, > >where is > >the Fermi level? It is ajusted to 0 eV, or still is the -5 eV? > > > >zero, the energies are simply shifted. > >M. > >-- >* * * * >Matteo Calandra, Charge de Recherche (CR1) >Institut de Min?ralogie et de Physique des Milieux Condens?s de Paris >Universit? Pierre et Marie Curie, tour 16, case 115 >4 Place Jussieu, 75252 Paris Cedex 05 France >Tel: +33-1-44 27 52 16 Fax: +33-1-44 27 37 85 >http://www.impmc.jussieu.fr/~calandra >___ >Pw_forum mailing list >Pw_forum at pwscf.org >http://www.democritos.it/mailman/listinfo/pw_forum >
[Pw_forum] Nscf calculation problem
Dear All, I met a problem with Nscf calculation. The K mesh i used is 12*12*12, and then there are 868 independent K points. But it takes about 450 seconds to calculate only one K point. If in this case, it will takes me 4.5 days to do such a nscf calculation. The tested energy cutoff i used is 60 Ry. Is there any way to accelerate the nscf calculation? If i'm right, the nscf calculation just take the charge density calculated from scf calculation, and there should be few way can accelerate the nscf calculation. Is it? Thanks for any help. Min Wu 2010-10-20 -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20101020/e775353b/attachment.htm
[Pw_forum] pseudopotential
Dear All, Since there are limited pseudopotentials available on the website of QE. Can we mix Norm-conserving pseudo and Ultrasoft pseudo in one calculation? Thanks. Min Wu 2010-10-20 -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20101021/57df3cc6/attachment.htm
[Pw_forum] xspectra calculation
Dear Matteo, When i cut the occupied state with "cut_occ_states=.true.", there is a small peak appeared at the energy of ef_r i set. In the element of "cut_occ", only cut_desmooth = 0.01 was set. The others are using default value. So what's the reason of this small peak? How to cut the occupied states smoothly? Thanks. With Regards, Min Wu 2010-10-23
