Re: [QE-users] Convergence with interstitials

Dear Tejas, There are many tests to check and test here. But one thing that comes to my mind is the pseudopotentials you used. you could try to use another set of pseudopotentials (especially for N). Try the recommended set here: https://www.materialscloud.org/discover/sssp/table/efficiency. Als

Re: [QE-users] Convergence with interstitials

Dear Tejas, Did you test giving an initial magnetic moment to N instead of W? For example: starting_magnetization(2)= 0.5 Regards, Mostafa AUC ___ Quantum ESPRESSO is supported by MaX (www.max-centre.eu) users mailing list users@lists.quantum-espres

Re: [QE-users] a problem related to the electric field calculations

Dear Samare, You are performing 'scf' calculation for Ti-doped Fe2O3 under electric field. This gives only the electron's response to the field. If you are interested in ions response (and in fact the ion-electron response) , you may need to use 'relax'. Of course make sure to relax the zero fi

Re: [QE-users] a problem related to the electric field calculations

Dear Rostami, As I explained in a recent thread, the raw dipole printed out by pw.x is not meaningful. One needs to post-process the results. Please see here: https://www.mail-archive.com/users@lists.quantum-espresso.org/msg39910.html Few other observations: 1- Your k-points mesh does not look co

Re: [QE-users] Finite electric field polarisation

Dear Terry, The dipole results need post-processing. One needs to subtract n x polarization quantum to obtain a meaningful polarization. n is an integer. Consider a simple dielectric like MgO at zero field. pw.x may give you different dipoles in all directions, although physically in all directi

[QE-users] Convergence with interstitials

Dear Tejas, I see two issues: 1) Your supercell size is too small. This corresponds to a high concentration of N. I would go for 4x4x4 conventional cells of W. That is 128 atoms. 2) A magnetic moment on N is needed since the odd number of electrons is because of N. Regards, Mostafa AUC ___

Re: [QE-users] magnetism in hematite (alpha-Fe2O3)

Dear all, There was a mistake in transforming the magnetic ordering from the primitive cell to the conventional cell. I fixed this and the results of both calculations agree. For the benefit of any readers I'm posting here the correct spin order on the Fe ions in the conventional cell: Fe1 0.

Re: [QE-users] magnetism in hematite (alpha-Fe2O3)

Dear Yasser, Thank you for your response and suggestion. I agree that DFT+U would improve the electronic structure of Fe-oxides, but the problem I'm facing is more related to symmetry. But to confirm this, I did actually try a quick DFT+U calculation and I still have the same problem that some ox

[QE-users] magnetism in hematite (alpha-Fe2O3)

ons in the conventional cell. Best Regards, Mostafa Youssef AUC - Egypt # Input file for the primitive cell &CONTROL calculation = 'vc-relax' , verbosity = 'high' , restart_mode = 'from_scratch' , prefix='fe2o3' , outdir='/data/mostafa/Fe2

Re: [Pw_forum] Problems computing cholensky

Dear Laurens, When I get this error, it is typically due to a parallelization issue. A quick fix that worked for me is using -ndiag 1 , so for example: pw.x_location -ndiag 1 output_file. Check the manual and forums for more details. Regards, Mostafa Youssef AUC, Egypt

Re: [Pw_forum] Zr supercell

Dear Krishnendu, If you model the alloy using a unit cell, then you are modeling a very high Nb concentration ordered alloy. Take HCP unit cell having two Zr atoms. If you replace one with Nb, then you get 50%-50% Zr-Nb. There is no way to avoid forming a supercell of Zr (Say 54 atoms) and then

Re: [Pw_forum] Problems Computing Cholesky for VC-Relax of MnO2

Dear Lance, When I get this error, it is typically due to a parallelization issue. A quick fix would be using -ndiag 1 , so for example: pw.x_location -ndiag 1 output_file. Check the manual and forums for more details. As a side, I highly doubt that these Mn and O pseudopotentials conver

Re: [Pw_forum] SCF calculations for molecules in electric fieldsare not converged

Dear Jibiao, If you would like to use modern theory of polarization (MTP) version of applying the electric field and reach 1 Ry a.u., then you can do this gradually. So converge 0.1 a.u., keep the wave functions, and use them as initial guess to 0.2 a.u.. Repeat with steps of 0.1 a.u. until you re

Re: [Pw_forum] SCF calculations for molecules in electric fields are not converged

Dear Jibiao Li, A field of 1 Ry a.u. is giant and atypical, so one should not be surprised do not converge. Recall, 1 in Ry a.u.=36.3609*10^10 V/m. I also noticed that you impose fixed occupations and then apply Gaussian smearing. Those are in contradiction of each other. Apparently the code en

[Pw_forum] Total & absolute magnetization in 2-atom unit cell and corresponding supercell

Dear AT Raji, A sample input file will help clarifying the issue. My guess is that you are dealing with a system with complex potential energy landscape and multiple local minima. If you know that the total magnetization has to be zero and you are using smearing, then try giving small magentizat

Re: [Pw_forum] Need help in spin polarized calculations

Dear Sayan, In the case of metallic systems, it is recommended to use smearing. With the smearing applied, you can use start_magnetization to give an initial guess for the magnetic moment. pw.x will try self-consistently to find the final magnetization that leads to minimum energy (Achieving b

Re: [Pw_forum] Need help in spin polarized calculations

Dear Sayan, 1- nspin=2 works whether you use LDA or GGA. 2- start_magnetization works when you apply smearing (occupation tag). Using this tag you give an initial guess and let the code to find the final magnetization associated with some nearby local energy minimum. tot_magnetization works

Re: [Pw_forum] Fwd: PAW pseudo for Mn

Dear Mohammadreza, Have a look at this link: http://materialscloud.org/sssp/ Also here: http://qe-forge.org/gf/project/pslibrary/ Regards, Mostafa ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum

Re: [Pw_forum] Phonon under pressure

Dear Subhodip, I'm no expert in high pressure physics and one needs to know the specifics of the system. How much pressure are you applying ? If too much the whole pseudopotential approach cannot be very helpful. Are you able to get reasonable phonons at zero pressure ? Do you anticipate pha

Re: [Pw_forum] Phonon under pressure

Dear Subhodip, If you maintain the lattice constant resulting from vc-relax then the pressure effect should be there in your phonon calculations. You apply the pressure by constraining the volume. Regards, Mostafa MIT ___ Pw_forum mailing list Pw_fo

Re: [Pw_forum] tot_charge in nano structures

Dear Zara, Have a look at : http://journals.aps.org/prx/abstract/10.1103/PhysRevX.4.031044 Regards, Mostafa MIT ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum

Re: [Pw_forum] Default color for xcrysden isosurface

Resolved. Clicking the box "Render +/- isovalue" restores the default red and blue colors. Mostafa ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum

[Pw_forum] Default color for xcrysden isosurface

Dear all, This is an Xcrysden usage question, but since most QE users use Xcrysden, I'm posting here as well. I'm using xcrysden version 1.5.60 on windows using cygwin. The default color for 3D isosurface is yellow. However, in older versions it was red (+) and blue (-). For consistency pur

Re: [Pw_forum] Charge of a supercell with a vacancy

Dear David, In experiments , neutral O2 gas leaves the TiO2 crystal causing the creation of oxygen vacancies behind. However, these vacancies can have any charge state. Neutral in which the two electrons (reminiscent of O2- ion) set around the vacancy forming polarons, 2+ in which the two ele

Re: [Pw_forum] substitution of positive charge into a negative charge.

calculating the formation energy of Nd defects in TiO2 requires a reference state for Nd; for example Nd2O3. Regards, Mostafa Youssef ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum

Re: [Pw_forum] External E-field Calculation for Bulk

Dear Mohammad, Yes you can simulate electric field effect on bulk 3D material. In pw.x input description check lelfield = .true. Also check these two papers: http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.89.157602 http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.89.117602 R

Re: [Pw_forum] Problem with charged defect calculation

Dear Evan, The postprocessing utility pp.x can calculate and plot the average potential as a function of x or y or z. This can help in performing the potential alignment. Regards Mostafa Youssef MIT ___ Pw_forum mailing list Pw_forum@pwscf.org http

[Pw_forum] Relax charged system

Dear Nkosinathi, Please send atomic positions and cell vectors and I can test it. Regards, Mostafa MIT ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum

Re: [Pw_forum] vc-relax not converge

I'm not very familiar with ESM model. But certainly modeling Na+ in water (or any insulator) requires tot_charge=+1. For MD , or relaxation nothing else is needed. Regards, Mostafa ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/m

Re: [Pw_forum] vc-relax not converge

Also note that you have one sodium atom and you did not set tot_charge to +1. So you are actually modeling Na+ and an electron. It is very difficult to predict the outcome of this calculation (metallic solution vs. insulating one) in a vc-relax calculation. If your goal is to model Na+, then t

Re: [Pw_forum] vc-relax not converge

Dear Nkosinathi, What is exactly not converging , the electronic minimization, or the ionic? Few things to note: 1- 90 H2O molecules +ion is 181 nat not 91. 2- It is a bit strange to use mp smearing typical for metals with liquid water. But it is unlikely that this is the cause of the problem

Re: [Pw_forum] force system to charge transferring

Dear Zara, Please have a look at this tutorial http://theossrv1.epfl.ch/Main/OxidationStates Regards, Mostafa MIT ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum

Re: [Pw_forum] vc-relax with homogeneous electric field

Dear Lei, If your material is does not exhibit large electrostriction and piezoelectric effect , then you can ignore changes in lattice parameter. Other wise you need to generate multiple curves (energy vs. volume) each curve has a different c/a ration. Where c is the direction parallel to th

Re: [Pw_forum] Error in charge difference

Dear Ozan, Make sure that all three files have same supercell vectors and same FFT grid. Mostafa MIT ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum

Re: [Pw_forum] Application of electric field to quantum dot

K_POINTS automatic 1 1 1 1 1 1 This works. Mostafa ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum

Re: [Pw_forum] Application of electric field to quantum dot

Dear Parham, I never studied quantum dots , so I cannot give a particular recommendation. But for the electric field in Berry phase formalism I can say that Gamma point only is not implemented in pw.x but it the default and only option in cp.x. In pw.x you can use one kpoint but it has to be

Re: [Pw_forum] charge density espresso 5.0.1

Dear Sakhraoui, The format of .XSF is explained here: http://www.xcrysden.org/doc/XSF.html You can plot rho_up -rho_down using plot_num=6 option in pp.x http://www.quantum-espresso.org/wp-content/uploads/Doc/INPUT_PP.html#idm6483344 Regards, Mostafa MIT ___

Re: [Pw_forum] Upper estimation of lattice parameter by LDA pseudopotential -regarding

Dear Suresh, I think the reason is the Ti pseudopotential. This one has 4 valence electrons and freezes the rest. This leads to larger ionic sizes and overestimation of the lattice constant. Allowing more Ti valence electrons, means further relaxation for the outer electronic shell and bet

Re: [Pw_forum] rectangular surface of Al2O3

Dear Andrey, I'm not particularly familiar with Al2O3 surfaces, but in general cutting rectangular surfaces can be accomplished in many cases by cutting the same surface from primitive cell instead of the conventional well. For example (111) is not rectangular in tetragonal Hf2O based on the

Re: [Pw_forum] Macroscopic Polarization

Dear Subhodip, Check example04 provided with pw.x. You can find it in: /Espresso_folder/PW/examples/example04 >From README: example04: This example shows how to calculate the polarization via Berry Phase in PBTiO3 (contributed by the Vanderbilt Group in Rutgers University). I wou

[Pw_forum] epsilon calculation in the case of a soft mode

lying a.s.r. Is there a way to enforce epsilon calculations based on frequencies after a.s.r application ? I'm using Q.E.5.2.0 but I believe recent versions do not have updates in this part of the code. Thank you, Mostafa Youssef MIT ___ Pw_for

Re: [Pw_forum] Band Offsets too large

Dear Dae Kwang Jun Equation (1) that you wrote is the correct one. And you are right bulk V_AlAs and bulk V_GaAs are obtained in a similar way as in the interface but you need bulk cells. Their values can be anything , positive or negative it does not matter and in fact they are arbitrary.

Re: [Pw_forum] Band Offsets too large

Dear Dae Kwang Jun In addition for each bulk calculation one needs to calculate the bulk average electrostatic potential. Then for each compound you refer its EVBM to the electrostatic potential calculated in its bulk (not yet the interface). Only then you can use the interface electrostati

Re: [Pw_forum] Band Offsets too large

Dear Dae Kwang Jun, You also need 2 bulk calculations for AlAs and GaAs to get their band edges with respect to to their bulk electrostatic potentials. Then you can use the interface potential to align the band edges of the two semiconductors. It looks like you missed this step. Mostafa MIT

Re: [Pw_forum] Band gap value through charged supercell calculation

Dear Evan, I would consult literature for that matter. It is very difficult and counterproductive to discuss this in an online forum. Mostafa ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum

Re: [Pw_forum] Band gap value through charged supercell calculation

Correction: I-A= E(N+1)+E(N-1)-2E(N) Mostafa ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum

Re: [Pw_forum] Question about electron (pseudo-)charge density calculations in QE

Dear Reza, If hydrogen can transform to Silicon than Quantum Espresso is an all Nucleon code that simulates Fusion :-) Check your Pseudo ! Regards, Mostafa MIT ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum

Re: [Pw_forum] Band gap value through charged supercell calculation

Dear Evan and Layla, E(N+x) where x is a real number can be calculated using tot_charge: http://www.quantum-espresso.org/wp-content/uploads/Doc/INPUT_PW.html#idm6396048 The ionization potential is not well-defined in bulk as Layla described but the difference I-A is well-defined for bulk. I-A

Re: [Pw_forum] Band gap value through charged supercell calculation

on the lattice parameters and supercells that the authors reported. In computing the K-S gap of a neutral cell I would use the tetrahedron method or fixed occupations (i.e no smearing) and a dense K-point mesh Regards, Mostafa Youssef MIT ___

Re: [Pw_forum] error in restarting pw.x

I think this thread is of such importance that it deserves to be part of the F.A.Q. section of the code. Optimal restart of pw.x to do relax or vc-relax calculations was always vague to me. Thanks a lot of clarification , Prof. Giannozzi ! Mostafa Youssef MIT

Re: [Pw_forum] Full k-points in Brillouin Zone (turning-off all symmetries)

Thank you for clarification, Ryky! Best Regards, Mostafa MIT ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum

Re: [Pw_forum] Full k-points in Brillouin Zone (turning-off all symmetries)

Dear Lorenzo and Ryky, Just out of curiosity does nosym=.TRUE. already implies noinv=.TRUE. ? I thought the former is enough to turn off all kinds of symmetries. Thank you, Mostafa Youssef MIT ___ Pw_forum mailing list Pw_forum@pwscf.org http

Re: [Pw_forum] Regarding Absolute band-edges

Dear Vipul, This is an old problem in semiconductor physics. In summary you need 2 set of calculations. One for a surface (interface) and another one for bulk. Key papers to review are: http://journals.aps.org/prb/abstract/10.1103/PhysRevB.35.8154 http://journals.aps.org/prl/abstract/10.1103/

Re: [Pw_forum] Regarding polarisation from Berry phase

Dear Varadharajan , This paper clarifies a lot of the ambiguities associated with determining the spontaneous polarization. Particularly the discussion around Fig. 9. http://arxiv.org/abs/1202.1831 Best, Mostafa ___ Pw_forum mailing list Pw_forum@

Re: [Pw_forum] negative occupations in DFT+U for nonmagnetic semiconductor

Thank you for the clarification, Prof. de Gironcoli. I think I misinterpreted the meaning of the matrix elements. Best Regards, Mostafa ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum

[Pw_forum] negative occupations in DFT+U for nonmagnetic semiconductor

e cell and the input file. Thank you, Mostafa Youssef MIT The matrices are: atom1 Tr[ns(na)] = 2.70769 eigenvalues: 0.142 0.177 0.182 0.417 0.436 eigenvectors: 0.675 0.000 0.000 0.325 0.000 0.000 0.000 0.500 0.000 0.500 0.000 0.000 0.500 0.000 0.500

Re: [Pw_forum] vc-relax problem

Dear David, In principle, starting from a 2D material and applying vc_relax should end up with the 3D version of the material. That is in the graphene case you should end up with graphite upon complete convergence. I doubt that this simulation is your intention here. If you would like , inst

Re: [Pw_forum] Ultrasoft or Norm conserinvg PP for Ce

ckage. Best Regards, Mostafa MIT From: Mehmet Topsakal [mtops...@umn.edu] Sent: Thursday, March 10, 2016 3:58 PM To: PWSCF Forum; Mostafa Youssef Subject: Re: [Pw_forum] Ultrasoft or Norm conserinvg PP for Ce Dear Mostafa, Please find our PAW potentials for rare-

[Pw_forum] Ultrasoft or Norm conserinvg PP for Ce

Dear all, I wonder if there is a reasonably performing Ce PP, US or NC , with 12 valence electrons and non-linear core correction. Thank you, Mostafa MIT ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum

Re: [Pw_forum] Spin-Polarized NEB

Thank you very much, Giuseppe ! Best Regards, Mostafa ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum

Re: [Pw_forum] Spin-Polarized NEB

Dear Giuseppe, The ethylene rotation example you mentioned is very interesting. I wonder if there is a reference you recommend that carefully analyzed this case with DFT or other quantum chemical approaches. Best Regards, Mostafa MIT ___ Pw_foru

Re: [Pw_forum] Oxidation state for dopants in TiO2

vation was discussed in this article: http://www.nature.com/nature/journal/v453/n7196/full/nature07009.html (It is also fun and instructive to follow the debate that this paper raised in literature!) Best Regards, Mostafa Youssef MIT ___ Pw_forum ma

Re: [Pw_forum] non-cubic dielectric tensor in a cubic crystal.

can help in clarifying this. Mostafa Youssef MIT ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum

Re: [Pw_forum] DOS Without 'Relax' ?

Dear Victor, I think there is nothing fundamentally wrong with calculating DOS from snapshots obtained from finite T MD. I also have seen this once in the literature from the work of Prof. A. Selloni group on TiO2/water interfaces somewhere around 2010. One could argue that even the single

Re: [Pw_forum] optimized Vanderbilt pseudos

Dear Stephan, The ONCV are norm conserving so 4*ecutwfc should be fine. Mostafa Youssef MIT ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum

Re: [Pw_forum] Band gap hybrid functionals

Dear Phil and all, Note that for a functional with exact exchange, the difference between ionization potential and electron affinity (I-A) is not the same as the Kohn-Sham single particle states gap. The consensus, as far as I know, is that I-A is more physical and relevant to comparison wit

Re: [Pw_forum] total energy for charged defects in semiconductors

Dear Manhong, As far I know the incosistency of treating charged defects within PAW formalism discussed in PHYSICAL REVIEW B 89, 045116 (2014) has not been resolved in any pseudopotential code. I wish I can devote more time to study this paper more carefully. Regarding the second paper, P

Re: [Pw_forum] DFT+U with static homogeneous finite electric field or Uniaxial tensile strain

Dear Yusuf, I'm not a developer but from my limited experience, I can tell that cell_dofree tag (the key to apply uniaxial strain) works well with DFT+U (With NC and USPP, I'm not sure about PAW). Finite electric field with DFT+U (NC and USPP) seems to work well too based on few tests I did

Re: [Pw_forum] Total potential under Berry phase electric field

This question is resolved. I understand a little better now that in small field regime one solves for polarized Bloch states and as such the charge density is indeed periodic. Mostafa ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mail

[Pw_forum] Total potential under Berry phase electric field

w the non-periodicity of the scalar potential is avoided. Any thoughts or references are highly appreciated. Mostafa Youssef MIT MgO_poential.pdf Description: MgO_poential.pdf ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/lis

Re: [Pw_forum] Finding the most stable structure

Dear Reza, Exploring the potential energy surface of glassy systems is not a trivial problem not to mention impurities in glassy systems. Depending on how deep you want to explore this, you may want to explore PLUMED package which is compatible with PWscf. http://www.plumed-code.org/ For som

Re: [Pw_forum] Temperature effect on band gap

Dear Reza, In addition to what Lorenzo suggested in relation to the accuracy of DFT in describing the band gap, there is a possibility that point defects can play a role in reducing the gap as the temperature increases. You might need to inspect the literature more to see how the observed re

Re: [Pw_forum] Force calculation time in relaxation under electric field

The last time report I quoted is with Hubbard U and this in fact what I typically find in PWscf relaxation calculation. I will send you the two output files offline. Thank you very much for your help! Regards, Mostafa MIT ___ Pw_forum mailing list Pw_

Re: [Pw_forum] Force calculation time in relaxation under electric field

Thank you for replying, Prof. Giannozzi. I'm using version 5.2.0, the system has 135 atoms of which 108 has U correction. I'm running it on 32 processors with 1 pool, a serial algorithm for Linear algebra to avoid "error in Cholesky decomposition", and 1 task group. I'm a bit surprised be

[Pw_forum] Force calculation time in relaxation under electric field

recommended possibility to reduce force calculation time? I attempted using Norm Conserving PP's but unfortunately I could not get the code pass the 1 ionic step because of the S matrix not being positive definite. I appreciate your thoughts on this. Regards, Mostafa Yousse

Re: [Pw_forum] Failed in tests and examples

Dear Fei As the message indicates there is a problem in reading the norm conserving pseudopotential file. I think this may also be the reason why example01 did not work because it uses NC PP for Si. Try the attached version of the H and O PP used in the H2O test. The attached worked for me. Or

Re: [Pw_forum] Choice of Pseudopotential

Hi Elham, Testing Pseudopotentials and choosing optimal ones is a daunting task that needs some serious work. In addition to the valuable advice you quoted from Prof. de Gironcoli, I'd add that converging total energy will lead you to a very safe e_cut and rho_cut but probably one can afford a

Re: [Pw_forum] Failed in tests and examples

Hi Fei Mao, Please post the error message in the file b3lyp-h2o.out. Apparently the test stopped when it encountered error message here. M. Y. MIT ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum

Re: [Pw_forum] Question on pseudopotential

Hi Sridhar, Of course you can do this mix. Please have a look at: http://www.quantum-espresso.org/faq/pseudopotentials/#2.3 M. Y. MIT ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum

Re: [Pw_forum] nscf+lelfield -----> Wrong k-string? Error

calculations. The first at zero field but still with lelfield=.true., the second starts from the wave functions generated from the first but has the magnitude of the field you would like to apply. Please see example 10 in PW/examples. Mostafa Youssef MIT

Re: [Pw_forum] Serial vs. parallel runs of berry.in test case

Thank you very much for fixing this, Prof. Giannozzi ! Best Regards, Mostafa Youssef MIT ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum

Re: [Pw_forum] Serial vs. parallel runs of berry.in test case

Thank you, Prof. Giannozzi. I tested one more time and found out that by removing tqr=.true. it works on 8 processors even with an FFT grid of 36x36x36. With tqr=.true. , the FFT grid has to be multiples of 8. Best Regards, Mostafa Youssef MIT

[Pw_forum] Serial vs. parallel runs of berry.in test case

overlapping or increase ecutrho And the code stops at the first scf step. When I double the energy and charge density cutoffs , it works well in parallel. This behavior is reproduced in versions 5.1.1, 5.1.2, and 5.2.0. Any thoughts on the possible reasons are appreciated. Thank you, Mostafa

Re: [Pw_forum] DFT+U calculations

U on TiO2 phonons. Mostafa Youssef MIT ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum

Re: [Pw_forum] DFT+U calculations

systematic investigation of the performance of DFT+U in predicting vibrational free energy *differences* between a perfect crystal (TiO2) and a defective one (TiO2-x) for this class of materials. I would be very interested if somebody can point out to a paper that addressed this. Mostafa

Re: [Pw_forum] DFT+U calculatoopns

approximation with Parlinski et al interpolation. Please follow the instructions on PHONOPY website. Mostafa YOussef MIT P.S. Somehow I read the title of your thread as DFT+U cartoons ! ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org

Re: [Pw_forum] tot_charge flag with DFT+U calculations

possible (of course starting from some initial guess). Mostafa Youssef MIT ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum

Re: [Pw_forum] Can I obtain IR spectrum from CPMD trajectory in Quantum Espresso?

the authors of this paper implemented Wannier on the fly which I think is not available in Q.E. But the computational cost to re-track the trajectory and calculate MLWF should not be too expensive if one already affords the MD run. Mostafa Youssef MIT

Re: [Pw_forum] How to calculate charged system binding energy?

Dear Bahadir First, charged slabs are problematic because their total energy does not converge with respect to vacuum thickness. You can test on a simple model. However, there is a trick to go around this by inserting a dopant far a way from the critical reaction zone. For example suppose you

Re: [Pw_forum] control strain calculations

>if you can please give me more details about how to control the number of cell >relaxed , because it is the same with >different press-conv-thr . for example I want to relax only the c axis keeping >a and b fixes, by using cell-dofree='z' , >but I would give the number of c which i want to relax

Re: [Pw_forum] Is geometry optimization same to MD?

Hi Shaofeng, Relaxation will give you "a" structure but most likely it is not a representative structure. MD will give you a set of possibly meaningful and representative solvation structures. If you average over these meaningful structures, you can get useful information about the solvation

Re: [Pw_forum] control strain calculations

Hi Imène, I guess the sopping criterion is press_conv_thr. http://www.quantum-espresso.org/wp-content/uploads/Doc/INPUT_PW.html#idp365664 Mostafa Youssef MIT <http://www.mail-archive.com/search?l=pw_forum@pwscf.org&q=from:%22Im%C3%A8ne+Ch%C3%A9ra%C3

Re: [Pw_forum] spin polarization

! Mostafa Youssef MIT ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum

Re: [Pw_forum] Ion

-content/uploads/Doc/INPUT_PW.html#idp110032 Mostafa Youssef MIT ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum

Re: [Pw_forum] HSE Si Lattice Parameter

Hi Galvin, Examining the energies and stresses you obtain from your calculations by the eye is not a very accurate way to obtain the lattice parameter that minimizes the energy and corresponds to a zero pressure. More accurate is to fit your results to an equation of state such as Birch-Murnagh

Re: [Pw_forum] Finite electric field (smearing , DFT+U, and total energy)

Thank you very much for addressing my questions, Prof. Giannozzi ! I will keep the mailing list updated if I succeed in reasonably getting smearing work with finite electric fields. Mostafa Youssef MIT ___ Pw_forum mailing list Pw_forum@pwscf.org

[Pw_forum] Finite electric field (smearing , DFT+U, and total energy)

under pressure. (Of course with the implicit warning that the enthalpy inherits the uncertainty in the polarization quantum). Thank you, Mostafa Youssef MIT ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum

Re: [Pw_forum] Negative Polarization !!!

lue of the spontaneous polarization of the material. A favorite of mine which go over some of these difficulties is this paper: http://journals.aps.org/prb/abstract/10.1103/PhysRevB.71.014113 Mostafa Youssef MIT ___ Pw_forum mailing list Pw_forum@pwsc

Re: [Pw_forum] PPs for V and Cs

Hi Carlo Both pslib0.31 (http://theossrv1.epfl.ch/Main/Pseudopotentials) and pslib1.0.0 (http://qe-forge.org/gf/project/pslibrary/) have relativistic PP for those two elements. Mostafa Youssef MIT ___ Pw_forum mailing list Pw_forum@pwscf.org http

Re: [Pw_forum] Questions related to Co and Fe Pseudopotentials in pslib 1and 0.31

Thank you very much for your reply, Prof. Dal Corso. And of course many thanks for the development of the library! Mostafa Youssef MIT ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum

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