Re: [QE-users] Does order of atoms matter in Quantum Espresso?

Thanks. I am trying to calculate the phonon dispersion of a superlattice consisting of InAs and AlSb. However, I am ending up with negative phonon frequencies for the structure. I used the epsil flag. But that did not help. How I can eliminate the negative phonon modes? For relaxation I am using t

Re: [QE-users] Does order of atoms matter in Quantum Espresso?

On Mon, Dec 30, 2019 at 11:08 PM Sheikh Ziauddin Ahmed wrote: I am trying to calculate the phonon dispersion of AlSb. I am getting two > different results depending on how I am introducing the atoms in the SCF > calculation. Will the order of the atom change the symmetry of the zinc > blende AlSb

Re: [QE-users] Does order of atoms matter in Quantum Espresso?

The commented lines are not wanted. On Mon, Dec 30, 2019 at 5:34 PM Andrea Ferretti wrote: > > Dear Sheikh Ziauddin Ahmed, > > the reordering of the atoms should not have an effect (besides the fact > ths you are also swapping the coordinates of the two atoms). > The biggest difference I see her

Re: [QE-users] Does order of atoms matter in Quantum Espresso?

Thank you all for your response. For computing the Z* and epilson for polar materials, I saw in a couple of tutorials that I have to first compute the dynamic matrix using dynmat.x at the Gamma point setting epsil=.true.. For the remaining q-points, I have to add the non-analytical part in the inp

Re: [QE-users] Does order of atoms matter in Quantum Espresso?

the order of the entries in the pseudopotential list or in the atomic position list should not affect the result. however you are not changing only the order. 1) you are also swapping the two atoms... this too should not change anything but is not the same as changing the order only :) 2) th

Re: [QE-users] Does order of atoms matter in Quantum Espresso?

Dear Sheikh Ziauddin Ahmed, the reordering of the atoms should not have an effect (besides the fact ths you are also swapping the coordinates of the two atoms). The biggest difference I see here is related to the smearing, which is commented in the second input.     !occupations='smearing',

[QE-users] Does order of atoms matter in Quantum Espresso?

I am trying to calculate the phonon dispersion of AlSb. I am getting two different results depending on how I am introducing the atoms in the SCF calculation. Will the order of the atom change the symmetry of the zinc blende AlSb? In the first case the input deck is: &system ibrav=2, nat=2, nt