[Pw_forum] Conversion of total energy to stress tensor
Dear QE developers and users, I have been able to calculate the total energy of crystalline structures under various strain tensors using pwscf. Now I intend to convert the total energy to stress tensors and then study the mechanical properties (either elastic or plastic) of different materials under strain (I have seen several papers that directly use E vs. Strain to calculate 2nd, 3rd, 4th, ... elastic constants and find yield & ultimate stress, but I believe that as Caro et al. http://dx.doi.org/10.1088/0953-8984/25/2/025803 mentioned, using Stress-Strain curve produces much accurate results). So, can anyone kindly give me some recommendation on how to convert Etot to Stress tensor? or Is there any tool to do this conversion? , since simply using (-dEtot/dVol) is not the solution Regards Afshin -- With Best Regards Afshin Arjhangemehr PhD student in Radiation Application Shahid Beheshti University G.C, Tehran, IRAN (+98) 912 439 20 64 ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
[Pw_forum] Unknown Symmetry Error in ph.x.
Dear All, I am getting an error as %% Error in routine find_mode_sym (1): unknown mode symmetry %% stopping ... unknown mode symmetry %% I am using PHONON v.5.4.0, the structure is a fully relaxed. The structure is a dumbell stanene. Regards,Ghadiyali Mohammed Kader ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
Re: [Pw_forum] Unknown Symmetry Error in ph.x.
You can use search_sym=.FALSE. in the phonon input to avoid this error, or provide the input so we can see what is happening. Andrea Quoting Mohammed Ghadiyali : > Dear All, > I am getting an error as > > %% > Error in routine find_mode_sym (1): unknown mode symmetry > %% > stopping ... unknown mode symmetry > %% > I am using PHONON v.5.4.0, the structure is a fully relaxed. The > structure is a dumbell stanene. > Regards,Ghadiyali Mohammed Kader ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
[Pw_forum] Conversion of total energy to stress tensor
Dear QE developers and users, I have been able to calculate the total energy of crystalline structures under various strain tensors using pwscf. Now I intend to convert the total energy to stress tensors and then study the mechanical properties (either elastic or plastic) of different materials under strain (I have seen several papers that directly use E vs. Strain to calculate 2nd, 3rd, 4th, ... elastic constants and find yield & ultimate stress, but I believe that as Caro et al. http://dx.doi.org/10.1088/0953-8984/25/2/025803 mentioned, using Stress-Strain curve produces much accurate results). So, can anyone kindly give me some recommendation on how to convert Etot to Stress tensor? or Is there any tool to do this conversion? , since simply using (-dEtot/dVol) is not the solution Regards -- With Best Regards Afshin Arjhangemehr PhD student in Radiation Application Shahid Beheshti University G.C, Tehran, IRAN (+98) 912 439 20 64 ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
[Pw_forum] problem with ph.x in calculating x-point phonon
Dear Experts, I hope all of you have a wonderful time, I used ph.x code to calculate photon of cubic phase (contain 40 atoms)at x-point. After running for a while, the code stopped and I got this message, ( the Fermi energy is 9.8719 ev Writing output data file ZovZu.save Possibly too few bands at point1 0.16667 0.16667 0.16667 Possibly too few bands at point2 0.16667 0.16667 1.16667 Possibly too few bands at point3 0.16667 0.16667 -0.5 Possibly too few bands at point4 0.16667 0.16667 0.5 Possibly too few bands at point5 0.16667 -0.5 -0.5 Possibly too few bands at point6 0.16667 -0.5 0.5 Possibly too few bands at point7 -0.5 -0.5 -0.5 Possibly too few bands at point8 -0.5 -0.5 0.5 Possibly too few bands at point9 -0.5 0.16667 0.16667 Possibly too few bands at point 10 -0.5 0.16667 1.16667 Possibly too few bands at point 11 -0.5 -0.5 0.16667 Possibly too few bands at point 12 -0.5 -0.5 1.16667 %% Error in routine set_irr_sym_new (5722): wrong representation %% stopping ... ) What do I have to do? Thank you in advance, Abdullah This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify Email System Administrator (e_ad...@uqu.edu.sa ) . Please note that any views or opinions presented in this email are solely those of the author and do not necessarily represent those of the Umm Al-Qura University. Finally, the recipient should check this email and any attachments for the presence of viruses. The Information Technology and Technical Support Center of Umm Al-Qura University accepts no liability for any damage caused by any virus transmitted by this email. ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
Re: [Pw_forum] Unknown Symmetry Error in ph.x.
Respected Sir, Thanks for the solution i.e your suggetion worked. And as per your instruction I am attaching my scf and ph.x inputs for your further analysis. Regards, Ghadiyali Mohammed Kader. >You can use search_sym=.FALSE. in the phonon input to avoid this >error, or provide the >input so we can see what is happening. > >Andrea > > >Quoting Mohammed Ghadiyali : > >> Dear All, >> I am getting an error as >> >> %% >>Error in routine find_mode_sym (1): unknown mode symmetry >> %% >> stopping ... unknown mode symmetry >> %% >> I am using PHONON v.5.4.0, the structure is a fully relaxed. The >> structure is a dumbell stanene. >> Regards,Ghadiyali Mohammed Kader d_sn_pd.in Description: Binary data d_sn_ph.in Description: Binary data ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
Re: [Pw_forum] Lower limit of target pressure
INPUT *press = 0.001* *press_conv_thr = 0.0001* OUTPUT *P (kbar) = 3.61* Best regards Subhodip On Sat, Sep 24, 2016 at 7:15 PM, Paolo Giannozzi wrote: > "A lot" = how much? the default tolerance on pressure convergence is 0.5 > KBar > > > Paolo > > On Sat, Sep 24, 2016 at 8:39 AM, Subhodip Chatterjee > wrote: > >> Dear PWSCF developers, >> >> Is there any restriction in the code for the "press" (target pressure) >> input? >> >> I successfully get my vc-relax calculations converged to desired pressure >> values as high as several terapascal, however, when I set a low enough >> value, e.g. 1 bar (i.e. press = 0.001), the final pressure in the output >> differs a lot! >> >> Best regards >> Subhodip >> >> -- >> *Subhodip Chatterjee* >> >> *Senior Research Fellow* >> >> *Department of Chemistry* >> *University of Calcutta* >> *Kolkata, India* >> >> ___ >> Pw_forum mailing list >> Pw_forum@pwscf.org >> http://pwscf.org/mailman/listinfo/pw_forum >> > > > > -- > Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche, > Univ. Udine, via delle Scienze 208, 33100 Udine, Italy > Phone +39-0432-558216, fax +39-0432-558222 > > > ___ > Pw_forum mailing list > Pw_forum@pwscf.org > http://pwscf.org/mailman/listinfo/pw_forum > -- *Subhodip Chatterjee* *Senior Research Fellow* *Department of Chemistry* *University of Calcutta* *Kolkata, India* ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
