[Pw_forum] Xe pseudopotentials
I just converted the pseudopotential of fhi of Zn and O.For O atom,I try this way: 2s 2 2p 4 3s 0 3p 0 For Xe atom, I think you can try 5s 2 5p 6 5d 0 5f 0 Best Regards Yun Song,Kang Physics Department of Inner Mongolia University P.R.China 2011/9/21 Chen, Zhifan > Hi all, > I am looking for Xe ultrasoft pseudopotential with 4d,5s,5p as > valence electrons. I can > Use ABINIT fhi pseudopotential and make conversion from fhi format to > USP. However, Xe NC pseudopotential has only 5s, 5p as valence electron. > I am new to the generate pseudopotential > . Any information is welcome. > > Thanks > > Zhifan Chen > Clark Atlanta University > USA > ___ > 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/20110923/edd4556a/attachment.htm
[Pw_forum] Does VCA method give positive formation energy?
Dear QE developers and users: Hi. I am using Quantum-ESPRESSO v4.2.1 to deal with DFPT and QHA. Because of the computational limitation of my PC, I chose VCA method to compare the phonon dispersion and thermo-properties change as a function of compositions. The system I calculated was ZrC-ZrN. Since based on our experiments, we have known that the Zr(CN) solid-solution is possible to produce. PW91 xc-functional has been selected at 13x13x13 k-points mesh with ecutwfc=40Ry and ecutrho=400Ry. The q-mesh was 4x4x4. Structure of ZrC, ZrN and Zr(CN) is Fm-3m (NaCl Structure). The Vanderbilt ultrasoft pseudo-potential of C and N were combined by virtual.x in certain ratio. However, I found the formation energy: Ff[T, Zr(CNx)] = F[T, Zr(CNx)] - (1-x) * F[T, ZrC] - x * F[T, ZrN] was always positive number. Then, I checked ZrC, ZrN and Zr(CN0.5) carefully by both of 'vc-relax' and E-V curve for total energy calculation. Finally, I found thatE[Zr(CN0.5)] - 0.5 * E[ZrC] - 0.5 * E[ZrN] was about +0.4Ry/cell, that means+525.088kJ/mol. According to thermodynamics principle, Zr(CN0.5) cannot be prepared. However, when I tried supercell-doping method, the formation energy was negative ( about-10kJ/mol ). Therefore, I want to know why VCA method gives positive formation energy. Is it reasonable? If it should be like this, then can we believe the phonon result from VCA as reliable one? Any suggestion will be welcomed. Thanks. -- GAO Zhe CMC Lab, MSE, SNU, Seoul, S.Korea -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20110923/b7d640da/attachment.htm
[Pw_forum] LDOS on parallel planes
Dear All, It is embarrassing for me to say that although I've read almost all emails in QE Archive on finding the local density of states on parallel planes of structures, I couldn't find a way to calculate them from your kind guidance. As far as I found, QE calculates the integrated local density of states in different energies (with post processing code). In ILDOS input file, it is possible to define different planes by ei(i), i=1,2,3. I was wondering whether by changing x0(i), i=1,2,3 (origin of the those planes defined by ei(i)), it would be possible to get the LODS on parallel planes. If positive, how can I possibly change x0(i) to get LDOS on parallel planes. Otherwise, if there is a way to find LDOS on parallel planes. I deeply appreciate your help. Yours P Shokri graduate student UMD -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20110923/6021a179/attachment.htm
[Pw_forum] LDA norm-conserving pseudopotential for Fe
Thanks so much for your help. I'll try some of these possibilities. > so YOU are from FHI, you should know what is inside those files... I'm from the Fritz-Haber Center for Molecular Research at the Hebrew Universitynot the same Fritz Haber Institute :) Helen This message was sent using IMP, the Internet Messaging Program.
[Pw_forum] band structure calculation
Bui, Have you taken a look at at example01, example13 and example22 in your espresso$VER/examples directory? also, Look at Thursday, 22 July in this page: http://users.aims.ac.za/~sandro/ On Fri, Sep 23, 2011 at 2:09 AM, Tram Bui wrote: > Dear Everyone, > I have run DOS calculation on my bulk SiC and I also wonder how to do > the band structure and plot the band structure. Would you give me some > information or some examples regarding generating the band structure? > > Thank you very much, > > Tram Bui > > M.S. Materials Science & Engineering > trambui at u.boisestate.edu > > > ___ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > > -- M. O. ATAMBO mikeat4999 at gmail.com M Phil. student, computational material science group Chepkoilel university college, Department of Physics, Eldoret, Kenya, -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20110923/3d776daf/attachment.htm
[Pw_forum] Symmetry problem in phonon
Dear All I have done phonon calculation of a BCT system. I have chosen 2x2x2 q mesh for phonon calculation. While in real space force constant calculation (q2r.x) I am getting the waring and it says " fft-check warning: sum of imaginary terms =10-6". i ignored it and calculate the phonon frequencies. From symmetry at zone boundary along 001 all the phonon frequencies are doubly degenerate which is experimentally observed but i didn't get the degeneracy. the frequencies at 001 are differ by about 1-5 meV. kindly advice. Thanks Mayank Research student BARC mumbai
[Pw_forum] stable phase
i am calulated b1 to b2 transition of some metal carbide i found b1 to b2 transition at 140 gpa from phonon dispersion i found dyanamical unstabilty at 140 gpa b1 phase but i am also found b2 is dyanamical unstable(in X and M) directions so i thought there must be other phase which may be stable at 140 gpa for this calculated L10 phase which will less enthalpy than b2 at 140 gpa but also this shows imaginary frequency in X direction so what is the stable phase? b d sahoo barc mumbai -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20110922/f727dc07/attachment.htm
