Dear Lorenzo, I appreciate your very useful comment. Effort is being made to ensure non negative frequencies.
Thanks a lot, Isaiah On Sat, Jul 29, 2017 at 10:50 AM, Lorenzo Paulatto < [email protected]> wrote: > I'm not an expert of this specific calculation, but I suspect that the > equation breaks down if even a tiny negative frequency is present. This > because energy conservation between phonons and electrons would not be > enforceable in a meaningful way. Sometimes, if the system has internal > degrees of freedom, a very fine relax calculation can remove negative > frequencies. Or if they arise from interpolation, changing the sum rule > method. > > -- > Lorenzo Paulatto > Written on a virtual keyboard with real fingers > > On 29 Jul 2017 10:15 a.m., "Isaiah Moses" <[email protected]> wrote: > > Dr Giovanni, > Thanks a lot. > I appreciate your response. > We observed few values of frequencies to be negative. > Matdyn1 has few more with others having either the first or the first 2/3 > to be negative. > We set those to be zero, modifying lambda.f90 code. > > Could that be the problem? > > I've attached the input/output for lambda.x execution. Also matdyn1 and 45. > > There are 62-points and 33 irreps. > I appreciate your time. > > On Fri, Jul 28, 2017 at 12:17 PM, Isaiah Moses <[email protected]> wrote: > >> Here is lambda.in and out. >> >> On Fri, Jul 28, 2017 at 12:13 PM, Isaiah Moses <[email protected]> >> wrote: >> >>> Dr Giovanni, >>> Thanks a lot. >>> I appreciate your response. >>> We observed few values of frequencies to be negative. >>> Matdyn1 has few more with others having either the first or the first >>> 2/3 to be negative. >>> We set those to be zero, modifying lambda.f90 code. >>> >>> Could that be the problem? >>> >>> I've attached the input/output for lambda.x execution. Also matdyn1 and >>> 45. >>> >>> There are 62-points and 33 irreps. >>> I appreciate your time. >>> >>> Isaiah >>> >>> On Fri, Jul 28, 2017 at 10:41 AM, Giovanni Cantele < >>> [email protected]> wrote: >>> >>>> Not that easy to answer without seeing relevant input/output files. >>>> >>>> As far as I know, Tc is quite difficult to converge. Did you made VERY >>>> VERY VERY careful checks on convergence with >>>> resect to ALL calculation parameters, starting from phonon frequencies? >>>> >>>> Giovanni >>>> >>>> >>>> On 28 Jul 2017, at 11:37, Isaiah Moses <[email protected]> wrote: >>>> >>>> Dear everyone, >>>> >>>> I did an el-ph calculation of a monoclinic structure and am getting >>>> really strange values of Tc . See the result below >>>> lambda omega_log T_c >>>> 0.00994 112.048 0.10012314E+08 >>>> 0.03760 92.373 0.13380511E+10 >>>> 0.07564 90.247 0.39802174E+19 >>>> 0.09959 89.414 0.19865362E+78 >>>> 0.11010 89.463 0.40671597-151 >>>> 0.11454 90.329 0.16986711E-65 >>>> 0.11678 92.320 0.99512429E-51 >>>> 0.11772 94.657 0.29927798E-46 >>>> 0.11744 97.141 0.16242032E-47 >>>> 0.11619 99.442 0.65514785E-54 >>>> >>>> I'm wondering why such values. >>>> >>>> Any comment shall be greatly appreciated. >>>> >>>> Thanks, >>>> Isaiah >>>> >>>> -- >>>> Isaiah Abu Moses >>>> Graduate Student, >>>> Physics Department, >>>> University of Ibadan, >>>> Nigeria >>>> >>>> >>>> >>>> -- >>>> Isaiah Abu Moses >>>> Graduate Student, >>>> Physics Department, >>>> University of Ibadan, >>>> Nigeria >>>> _______________________________________________ >>>> Pw_forum mailing list >>>> [email protected] >>>> http://pwscf.org/mailman/listinfo/pw_forum >>>> >>>> >>>> -- >>>> >>>> Giovanni Cantele, PhD >>>> CNR-SPIN >>>> c/o Dipartimento di Fisica >>>> Universita' di Napoli "Federico II" >>>> Complesso Universitario M. S. Angelo - Ed. 6 >>>> Via Cintia, I-80126, Napoli, Italy >>>> e-mail: [email protected] >>>> Phone: +39 081 676910 <+39%20081%20676910> >>>> Skype contact: giocan74 >>>> >>>> ResearcherID: http://www.researcherid.com/rid/A-1951-2009 >>>> Web page: http://people.fisica.unina.it/~cantele >>>> >>>> >>>> _______________________________________________ >>>> Pw_forum mailing list >>>> [email protected] >>>> http://pwscf.org/mailman/listinfo/pw_forum >>>> >>> >>> >>> >>> -- >>> Isaiah Abu Moses >>> Graduate Student, >>> Physics Department, >>> University of Ibadan, >>> Nigeria >>> >> >> >> >> -- >> Isaiah Abu Moses >> Graduate Student, >> Physics Department, >> University of Ibadan, >> Nigeria >> > > > > -- > Isaiah Abu Moses > Graduate Student, > Physics Department, > University of Ibadan, > Nigeria > > _______________________________________________ > Pw_forum mailing list > [email protected] > http://pwscf.org/mailman/listinfo/pw_forum > > > > _______________________________________________ > Pw_forum mailing list > [email protected] > http://pwscf.org/mailman/listinfo/pw_forum > -- Isaiah Abu Moses Graduate Student, Physics Department, University of Ibadan, Nigeria
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