Re: [Pw_forum] Unit-cell and Super-cell bandgap difference

Dear Vipul, how many k-points did you use for the cell and for the supercell Best Dario On Thu, Nov 24, 2016 at 6:23 AM, Vipul Shivaji Ghemud < vi...@physics.unipune.ac.in> wrote: > Hi all, > I am working on a system of 9atoms in a unit-cell having bandgap of 3.5eV; > but I am considering the

[Pw_forum] Unit-cell and Super-cell bandgap difference

Hi all, I am working on a system of 9atoms in a unit-cell having bandgap of 3.5eV; but I am considering the super-cell(4 unit-cells) then the bandgap is reduced by ~0.45eV for HSE06. The bandgaps are similar with GGA. Is it due to the exchnage-correlation contribution of the increased number of

Re: [Pw_forum] the error: "ortho went bananas" in cp.x run

Dear Paolo，When I use Gram-Schmidt, I am able to run cp.x .Before I run cp.x ,the atomic coordinate is orderd. But when I use Gram-Schmidt,I don't know why the atomic coordinate is disorderd. That means the molecular structure is disorderd.I try to change the input file description (reduce the

[Pw_forum] Convergence

Dear all, I'm trying to calculate difference in total energy of two structures of TM silicate, but every time get different result. I used internal optimization "relax" and then "vc-relax", only "vc-relax" etot_conv_thr 1.0d-4, 1.0d-5, 1.0d-3 force conv threshold 1.0d-3 Cell factor 1.5, 2.0, omit

Re: [Pw_forum] epsilon.x

Dear Pashangpour, what I meant is that the meaning of the variables intersmear and intrasmear of epsilon is quite similar to that of degauss in DOS or projwfc, and that convergences should be studied in a similar way... (note that very often kpt meshes denser than those used for scf runs are

[Pw_forum] Total energy calculation

Dear all, I'm trying to calculate difference in total energy of two structures of TM silicate, but every time get different result. I used internal optimization "relax" and then "vc-relax", only "vc-relax" etot_conv_thr 1.0d-4, 1.0d-5, 1.0d-3 force conv threshold 1.0d-3 Cell factor 1.5, 2.0, omit

Re: [Pw_forum] epsilon.x

Dear Ferretti I mean inter and intera smearings in inputpp of epsilon calculation not in inputscf. Do you mean I can set them similar kpt, Ecuts and smearing in scf input? Thanks M Pashangpour IIAU,Tehran,Iran Sent from my iPhone > On 23 Nov 2016, at 19:56, Andrea Ferretti

Re: [Pw_forum] epsilon.x

Dear Pashangpour, the idea is very similar to the usual kpt convergence vs smearing parameter for a DOS calculation. At variance with scf runs, here you are computing a spectral quantity (the dielectric function as a function of the frequency), meaning that you may need a (much) finer mesh

Re: [Pw_forum] problem with DFT+U

Dear Paolo, Unfortunately, there's not much to report so far. Many "relax" jobs for a system of ca. 500 atoms (including Fe) fail giving the same message Davide reported long time ago: _ Fatal error in PMPI_Bcast: Other MPI error, error stack: PMPI_Bcast(2434):

Re: [Pw_forum] problem with DFT+U

Thank you, but unless an example demonstrating the problem is provided, or at least some information on where this message come from is supplied, there is close to nothing that can be done Paolo On Wed, Nov 23, 2016 at 10:05 AM, Sergi Vela wrote: > Dear Colleagues, > >

Re: [Pw_forum] QE 6.0 slower than 5.4 ??

Hi Francesco, in order to have performance reproducibility be sure to: -disable hyperthreading -disable node health check mechanism In both cases I experienced a slowdown up to a factor 2. You also mention that you see slowdown while using threads. The system you mention looks way to small to

Re: [Pw_forum] QE 6.0 slower than 5.4 ??

I do not think anything has been done that negatively affects speed of execution. Before taking seriously any claim on increased or decreased speed due to X, I want to see a "diff" of two runs made with different X and all other conditions unchanged; plus a few different runs of the same code

Re: [Pw_forum] VC-relax collapsing unit cell

I made a quick test with USPP's. The unit cell shrinks about 10%. Paolo On Tue, Nov 22, 2016 at 4:56 PM, John Bilgerman wrote: > Thanks for the tip. I'd only tried up to about a hundred in my tests, I'll > start looking even higher. I attempted this over the weekend on

[Pw_forum] QE 6.0 slower than 5.4 ??

Hi Dear community, I have a question...Since the qe 6.0 release i started to use it, and I noticed a slow down for systems up to 48 atoms / 100 electrons running on few cores, and a speed up running upon more cores. I other words, taking as example an insulator polymer, set in its lattice

Re: [Pw_forum] Running in Parallel

On Nov 22, 2016, at 11:48 PM, Mofrad, Amir Mehdi (MU-Student) wrote: > After I compiled version 6 I can't run it in parallel. A bit more information about how you compiled and how your run will be useful to understand your problem -- Filippo SPIGA ~ Quantum ESPRESSO

Re: [Pw_forum] problem with DFT+U

Dear Colleagues, Just to report that I'm having exactly the same problem with DFT+U. The same message is appearing randomly only when I use the Hubbard term. I could test versions 5.2 and 6.0 and it occurs in both. All my best, Sergi 2015-07-16 18:43 GMT+02:00 Paolo Giannozzi