Re: [Pw_forum] problem

Sir, I am a phd scholar from India, Sir i am getting problem while installing "Quantum Espresso" so kindly help me for installation of the same.. Thank You Suryakant Mishra Indian Institute of Technology Indore On Wed, Jul 8, 2015 at 10:20 AM, Surykant Mishra wrote:

Re: [Pw_forum] How to select unit cell for optimization calculation?

Dear Max, You can use the following 14 atoms coordinates for spinel AB2O4 (fd-3m origin choice 2), replace "x" with oxygen parameter from 32e wykoff site (0.2627 for your case) A0.125 0.125 0.125 A0.875 0.375 0.375 B0.5 0.5 0.5 B0.250.75

Re: [Pw_forum] How to select unit cell for optimization calculation?

Thanks for your help. I read in mail-archive.com that this spinel work fine with 2 formula units but I cannot found how reducre from 8 formula units to 2 formula units. On Tue, Jul 7, 2015 at 5:33 AM, Giovanni Cantele < giovanni.cant...@spin.cnr.it> wrote: > if you want to optimize the

Re: [Pw_forum] (no subject)

QE with meta-GGA functionals is very unstable, due to numerical problems of uncler origin (or maybe the origin is clear, it is the solution that is not) Paolo On Tue, Jul 7, 2015 at 6:22 PM, Khalid Ibne Masood Khalid wrote: > Dear Researchers, > I was trying to calculate

[Pw_forum] (no subject)

Dear Researchers, I was trying to calculate the band gap of a 2D material using 'TB09' metaGGA. I have successfully installed libxc and linked it with quantum espresso, but upon running the pw.x file, it shows: Error in routine cdiaghg (189): S matrix not positive definite I have seen

Re: [Pw_forum] How to calculate piezoelectric constants

It used to be coded as post processing of the Phonon code but not any more. It should be possible to compute the change in macroscopic polarization induced by a deformation by the Berry phase approach. Or calculate the stress induced by a finite electric field [see e.g. Umari, Pasquarello PRL

Re: [Pw_forum] How to calculate elastic constants?

I would use the strain-stress relationship to extract the elastic constants from distorted crystals. pay attention to properly include relaxation of internal degrees of freedom stefano On 07/07/2015 15:42, Mojtaba Mirseraji wrote: > Dear ESPRESSO users and developers > > I want to know how to

Re: [Pw_forum] How to calculate Born effective charges ?

you can use the phonon code to calculate the Born effective charges. A good place to look for the theory involved is Phonons and related crystal properties from density-functional perturbation theory By: Baroni, S; de Gironcoli, S; Dal Corso, A; Giannozzi, P. REVIEWS OF MODERN PHYSICS 73,

Re: [Pw_forum] How to calculate elastic constants?

Dear ESPRESSO users and developers I want to know how to calculate elastic constants (C33, C12, C13,C44,C66 ...) ! Do you have any good paper that explain them step by step and easily? Regards Mojtaba Mirseraji Ph.D. Candidate Physics Department Arak Univ. I.R.IRAN On 6/23/15, Mojtaba

Re: [Pw_forum] How to calculate piezoelectric constants

Dear ESPRESSO users and developers I want to know how to calculate piezoelectric constants (d33, d31, d15, ...) ! Do you have any good paper that explain them step by step and easily? Regards Mojtaba Mirseraji Ph.D. Candidate Physics Department Arak Univ. I.R.IRAN On 6/23/15, Mojtaba Mirseraji

Re: [Pw_forum] How to calculate Born effective charges ?

Dear ESPRESSO users and developers I want to know how to calculate Born effective charges for all ions and atoms ! Do you have any good paper that explain them step by step and easily? Regards Mojtaba Mirseraji Ph.D. Candidate Physics Department Arak Univ. I.R.IRAN On 6/23/15, rauleg

Re: [Pw_forum] phonon q2r problem

On Tue, Jul 7, 2015 at 2:09 PM, Ludwig, Stephan < stephan.lud...@pi1.physik.uni-stuttgart.de> wrote: > Does this mean I can't run q2r on clusters?` > not necessarily so. It might also be a memory problem, although it shouldn't use that much memory (at least, not for asr='simple'). Try to copy

Re: [Pw_forum] phonon q2r problem

Thank you for your reply. I know that q2r is not parallel. I'm working on a cluster with a queuing-system and (MOAB). I defined to run on a single node with one proc and  yet I got the error-message. Does this mean I can't run q2r on clusters? Thanks and regards Stephan

Re: [Pw_forum] How to select unit cell for optimization calculation?

if you want to optimize the structure (that is, the lattice constant), I would say that you cannot use few atoms. Convergence of the total energy with respect to the cutoff is a property of the pseudo potentials, so you could check the variations of the total energy with respect to ecutwfc by

Re: [Pw_forum] How to select unit cell for optimization calculation?

Thanks for the fast response. *definitely need 56 atoms*. Thats mean that cannot use few atoms for convergence test and optimize the structure. If you can, can you suggest me some tricks for convergence test with this lot of atoms? I need run relax calculation before run scf for ecut and alat

Re: [Pw_forum] How to select unit cell for optimization calculation?

As far as I understand, the LiMn2O4 has 8 formula units in one unit cell, so you definitely need 56 atoms in the unit cell. The cif file contains only information on the inequivalent atoms, all others can be obtained from the former by applying the coordinate transformation of the space group