Hi, My name is Tram Bui and i'm new to the forum so i'm not quite sure how the Q&A work, but today I want to try the forum with my very first question is that: If i want to calculate the total energy based on lattice parameters of SiC, how do you determine (or find) the ecutoff (kinetic energy cutoff of wave function) value for a material structure such as SiC?
Thank you, Tram On Wed, Oct 13, 2010 at 4:54 AM, Shyam Khambholja <physik.shyam at gmail.com>wrote: > Thank you Prof. Stefano, > how to calculate energy of an isolated > atom ? > > shyam > > > On Wed, Oct 13, 2010 at 2:32 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: Pw_forum Digest, Vol 40, Issue 19 (matteo calandra) >> 2. cohesive energy (Shyam Khambholja) >> 3. Re: Question about Young's modulus (Mahdi Mirnezhad) >> 4. Re: Question about Young's modulus (Stefano de Gironcoli) >> 5. Re: cohesive energy (Stefano de Gironcoli) >> 6. pw.x crash on LSF/mvapich (Kiss, Ioan) >> >> >> ---------------------------------------------------------------------- >> >> Message: 1 >> Date: Tue, 12 Oct 2010 10:14:42 +0200 >> From: matteo calandra <matteo.calandra at impmc.jussieu.fr> >> Subject: Re: [Pw_forum] Pw_forum Digest, Vol 40, Issue 19 >> To: pw_forum at pwscf.org >> Message-ID: <20101012101442.84091vx35nxcb3zm at www1.impmc.upmc.fr> >> Content-Type: text/plain; charset=ISO-8859-1; DelSp="Yes"; >> format="flowed" >> >> Dear Min Wu, >> >> I think you should sit down a bit and try to solve this issue >> by yourself. This is not a problem concerning the code as you would have >> the same problem with any other code, but it concerns basic >> physics and group theory. >> In the future we plan to write a program to find the isotropic cross >> section >> with the sallest number of calculations possible from the knowledge of >> the symmetries of the lattice. >> However this is not yet done (I am not aware of any program doing this). >> >> So, as I always do in these case, you should si down,try to understand >> Ch. Bouder's paper and find the polarization vectors necessary to >> obtain the isotropic cross section. >> >> M. >> >> > >> > Message: 6 >> > Date: Tue, 12 Oct 2010 14:59:33 +0800 >> > From: "wumindt2" <wumindt2 at zju.edu.cn> >> > Subject: Re: [Pw_forum] Xspectra calculation (wumindt2) >> > To: pw_forum at pwscf.org >> > Message-ID: <CTFHHDRTTMMZGMEUQITYAFBYXCPW.wumindt2 at zju.edu.cn> >> > Content-Type: text/plain; charset="gb2312" >> > >> > 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 <matteo.calandra at impmc.jussieu.fr> >> >> Reply-To: PWSCF Forum <pw_forum at pwscf.org> >> >> 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 mailing list >> > Pw_forum at pwscf.org >> > http://www.democritos.it/mailman/listinfo/pw_forum >> > >> > >> > End of Pw_forum Digest, Vol 40, Issue 19 >> > **************************************** >> > >> >> >> >> ---------------------------------------------------------------- >> This message was sent using IMP, the Internet Messaging Program. >> >> >> >> >> ------------------------------ >> >> Message: 2 >> Date: Tue, 12 Oct 2010 17:36:25 +0700 >> From: Shyam Khambholja <physik.shyam at gmail.com> >> Subject: [Pw_forum] cohesive energy >> To: pw_forum at pwscf.org >> Message-ID: >> <AANLkTimSwcsJ1VosFZGQSotksAiHyV_c6SqfycreAmHd at mail.gmail.com> >> Content-Type: text/plain; charset="iso-8859-1" >> >> Hello all, >> scf calculation can give us total energy. but how to calculate >> cohesive energy of elements like aluminium from total energy ? thanks in >> advance >> >> -- >> Mr. Shyam G Khambholja >> Research student, >> Depratment of Physics, >> Sardar Patel University, Gujarat >> -------------- next part -------------- >> An HTML attachment was scrubbed... >> URL: >> http://www.democritos.it/pipermail/pw_forum/attachments/20101012/8cf3d73e/attachment.html >> >> ------------------------------ >> >> Message: 3 >> Date: Tue, 12 Oct 2010 16:25:00 +0330 >> From: Mahdi Mirnezhad <mirnezhad.mm at gmail.com> >> Subject: Re: [Pw_forum] Question about Young's modulus >> To: pw_forum <pw_forum at pwscf.org> >> Message-ID: >> <[email protected]> >> Content-Type: text/plain; charset=ISO-8859-1 >> >> Dear Developers, >> I think there is a problem in the calculation of stress in Quantum >> Esperesso. This problem concern with the volume of unit cell. For bulk >> structures there is no problem for determination of Volume but in the >> super cell method code calculate stress according to unit cell volume >> so when i calculate Young's Modulus for graphene with two method >> (strees/strain or (E=(1/V)*second derivative of energy) ) i get >> different answer. >> What is your suggestion? >> Thanks for your reply. >> >> Mahdi Mirnezhad >> Msc student of Mechanics >> Guilan University. >> >> >> >> On 10/7/10, Mahdi Mirnezhad <mirnezhad.mm at gmail.com> wrote: >> > Dear all, >> > I calculated Young's modulusfor graphene and i got correct answer but >> > when I want to calculate Young's modulus for CNT(3,3) for a axial >> > strain with the same condition (same PS) i got a wrong answer? >> > Any suggestion appreciated, >> > tanks >> > >> > mahdi mirnezhade >> > >> >> >> ------------------------------ >> >> Message: 4 >> Date: Tue, 12 Oct 2010 15:01:29 +0200 >> From: Stefano de Gironcoli <degironc at sissa.it> >> Subject: Re: [Pw_forum] Question about Young's modulus >> To: PWSCF Forum <pw_forum at pwscf.org> >> Message-ID: <4CB45C29.6070908 at sissa.it> >> Content-Type: text/plain; charset=ISO-8859-1; format=flowed >> >> for a 2-D system I guess that the definition of stress will involve the >> area and not the volume ... >> stefano >> >> >> Mahdi Mirnezhad wrote: >> > Dear Developers, >> > I think there is a problem in the calculation of stress in Quantum >> > Esperesso. This problem concern with the volume of unit cell. For bulk >> > structures there is no problem for determination of Volume but in the >> > super cell method code calculate stress according to unit cell volume >> > so when i calculate Young's Modulus for graphene with two method >> > (strees/strain or (E=(1/V)*second derivative of energy) ) i get >> > different answer. >> > What is your suggestion? >> > Thanks for your reply. >> > >> > Mahdi Mirnezhad >> > Msc student of Mechanics >> > Guilan University. >> > >> > >> > >> > On 10/7/10, Mahdi Mirnezhad <mirnezhad.mm at gmail.com> wrote: >> > >> >> Dear all, >> >> I calculated Young's modulusfor graphene and i got correct answer but >> >> when I want to calculate Young's modulus for CNT(3,3) for a axial >> >> strain with the same condition (same PS) i got a wrong answer? >> >> Any suggestion appreciated, >> >> tanks >> >> >> >> mahdi mirnezhade >> >> >> >> >> > _______________________________________________ >> > Pw_forum mailing list >> > Pw_forum at pwscf.org >> > http://www.democritos.it/mailman/listinfo/pw_forum >> > >> >> >> >> ------------------------------ >> >> Message: 5 >> Date: Tue, 12 Oct 2010 15:07:28 +0200 >> From: Stefano de Gironcoli <degironc at sissa.it> >> Subject: Re: [Pw_forum] cohesive energy >> To: PWSCF Forum <pw_forum at pwscf.org> >> Message-ID: <4CB45D90.9030502 at sissa.it> >> Content-Type: text/plain; charset=ISO-8859-1; format=flowed >> >> the cohesive energy is the energy per atom of the bulk minus the energy >> of an isolated atom. >> stefano >> >> Shyam Khambholja wrote: >> > Hello all, >> > scf calculation can give us total energy. but how to >> calculate >> > cohesive energy of elements like aluminium from total energy ? thanks >> in >> > advance >> > >> > >> > ------------------------------------------------------------------------ >> > >> > _______________________________________________ >> > Pw_forum mailing list >> > Pw_forum at pwscf.org >> > http://www.democritos.it/mailman/listinfo/pw_forum >> > >> >> >> >> ------------------------------ >> >> Message: 6 >> Date: Tue, 12 Oct 2010 18:02:00 +0000 >> From: "Kiss, Ioan" <kissi at uni-mainz.de> >> Subject: [Pw_forum] pw.x crash on LSF/mvapich >> To: "pw_forum at pwscf.org" <pw_forum at pwscf.org> >> Message-ID: >> < >> C2A03FEA95390F46839DC92BB46F57741D19C449 at e14mdb-01.zdv.Uni-Mainz.DE> >> Content-Type: text/plain; charset="iso-8859-1" >> >> Dear PWSCF users and developers, >> >> I have a problem running pw.x in our computer center. >> The MPI environment is mvapich_1.1, the queuing system is LSF, and I have >> compiled PWSCF with the Intel compiler suite together with MKL libraries. >> The threading via MKL is turned off by exporting OMP_NUM_THREADS=1. >> The machines are 8 core Xeons with QDR Infiniband and 48GB of ECC >> memory/node. >> >> I would like to perform some geometry optimizations on Cd doped >> CuInSe2 with PWSCF version 4.1.2. >> The FFT grid for the respective slab is 150:150:144, and it does run >> on 24 CPUs (i.e. 3 nodes with 8 cores). >> However, by taking the same binary and input file, if I would like to use >> 48, 72 >> or 144 CPU cores, than the job will crash right after the WFC >> initialization: >> >> Self-consistent Calculation >> >> iteration # 1 ecut= 25.00 Ry beta=0.70 >> Davidson diagonalization with overlap >> Signal 15 received. >> . >> . >> . >> Signal 15 received. >> Job /usr/local/lsf/7.0/linux2.6-glibc2.3-x86_64/bin/mvapich_wrapper >> VIADEV_USE_SHMEM_ALLREDUCE=0 >> VIADEV_USE_SHMEM_REDUCE=0 VIADEV_USE_SHMEM_BARRIER=0 >> DISABLE_RDMA_ALLTOALL=1 >> DISABLE_RDMA_ALLGATHER=1 DISABLE_RDMA_BARRIER=1 >> MV2_CPU_MAPPING=0:1:2:3:4:5:6:7 ./pwTest.x -in INP-PWSCF >> >> TID HOST_NAME COMMAND_LINE STATUS >> TERMINATION_TIME >> ===== ========== ================ ======================= >> =================== >> 00000 moment1 /usr/local/lsf/l Exit (1) 10/12/2010 >> 19:20:36 >> . >> . >> . >> 00001 moment1 /usr/local/lsf/l Exit (174) 10/12/2010 >> 19:20:36 >> >> As you can see, I have already tried to deactivate the shared memory >> optimizations >> implemented in mvapich in the Nemesis routines, but that did not help >> either. >> Strangely, on the same machine I can run CPMD without any issues, so I am >> really wondering >> what I am doing wrong or what should I change to fix this problem. I have >> tried several different >> MKL versions and so forth, but to be honest it seems to me that I just >> cannot fix it. >> Also, using the same input file and 48-72 CPUs the job will nicely finish >> in Juelich supercomputer >> center and also in the department's tiny local cluster running OpenMPI. >> >> Do you have some ideas why the machine under LSF/mvapich is not fully >> cooperating with >> PWSCF above 24 CPU cores, or what should be done to remedy this issue? >> >> >> Thanks in advance for any helpful comment, >> >> Janos. >> >> >> ========================================== >> Dr. Janos Kiss e-mail: kissi at uni-mainz.de >> Johannes Gutenberg-Universitaet >> Institut f. Anorg. u. Analyt. Chemie >> AK Prof. Dr. Claudia Felser >> Staudinger Weg 9 / Raum 01-230 >> 55128 Mainz/ Germany >> Phone: +49-(0)6131-39-22703 >> Fax: +49-(0)6131-39-26267 >> Web: http://www.superconductivity.de/ >> ========================================= >> >> >> ------------------------------ >> >> _______________________________________________ >> 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 20 >> **************************************** >> > > > > -- > Mr. Shyam G Khambholja > Reseach student, > Depratment of Physics, > Sardar Patel University, Gujarat > Cell No. : +91 999 888 3867 > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > > -- Tram Bui B.S. Materials Science & Engineering trambui at u.boisestate.edu -------------- next part -------------- An HTML attachment was scrubbed... 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