[Pw_forum] Computing Second order response
well, you probably know more than I do, but the cross section for (off-resonant) Raman scattering is basically the derivative of the dielectric constant with respect to the amplitude of the vibrational distortion. I do not know what exactly is measured (you probably do), but this is what is calculated, and the dielectric tensor of a metal is infinite ... in any case, it is always a good idea to know what is measured (which I don't, in this case), and what is calculated (which you do not seem to do, in this case ...). graphene may be another story, because the density of states at the fermi energy is zero ... Stefano B On Jun 15, 2010, at 2:56 PM, loc duong ding wrote: > I don't understand why Raman activity in this case is zero. In practical, > metallic system also provide Raman peak (ex. Carbon nannotube). I try to > calculate graphene (no gap) and I get the proper result. Can you give some > more explanation or suggest me some reference about this topic? > > I appreciate to your instructions. > >> So, the the Raman activity should be >> zero ... >> SB > > On Jun 15, 2010, at 3:50 AM, loc duong ding >> wrote: > >> I calculate zigag nano ribbon with hydrogen terminated at the >> edge. I checked DOS that showed no gap. >> >>> yes - SB >> >> >> On Jun 14, 2010, at 11:03 AM, loc duong ding >> wrote: >> what's the gap of the >>> unperturbed >> system? SB >>> >>> Actually, >> this >>> is the firs time I calculate the Raman spectrum. I don't clear >> about the gap of >>> the unperturbed system? It means the electronic >> band gap? > > > --- > Loc Duong Dinh > Ms-Ph.D Student > Sungkyunkwan Advanced Institute of Nanotechnology, > Sungkyunkwan University, > Suwon, 440-746, Korea > Email: mambom1902 at yahoo.com, ddloc at skku.edu > > > > ___ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum --- Stefano Baroni - SISSA & DEMOCRITOS National Simulation Center - Trieste http://stefano.baroni.me [+39] 040 3787 406 (tel) -528 (fax) / stefanobaroni (skype) La morale est une logique de l'action comme la logique est une morale de la pens?e - Jean Piaget Please, if possible, don't send me MS Word or PowerPoint attachments Why? See: http://www.gnu.org/philosophy/no-word-attachments.html -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20100615/c8219b04/attachment.htm
[Pw_forum] Computing Second order response
so, the the Raman activity should be zero ... SB On Jun 15, 2010, at 3:50 AM, loc duong ding wrote: > I calculate zigag nano ribbon with hydrogen terminated at the edge. I checked > DOS that showed no gap. > >> yes - SB > > On Jun 14, 2010, at >>> 11:03 AM, loc duong ding wrote: > >>> what's the gap of the >> unperturbed >>> system? >>> SB >> >> Actually, this >> is the firs time I calculate the Raman spectrum. I don't clear about the gap >> of >> the unperturbed system? It means the electronic band gap? >> >> I >> appreciate to your explanation. I am sorry about my late reply. >> >> >> >> On May 31, 2010, at 6:10 PM, loc duong ding >> wrote: >> Dear all, >> I want calculated IR and Raman of nanoribbon. >> The problem is when the code calcualtion second order response, it >> is not convergence. > > --- > Loc Duong Dinh > Ms-Ph.D Student > Sungkyunkwan Advanced Institute of Nanotechnology, > Sungkyunkwan University, > Suwon, 440-746, Korea > Email: mambom1902 at yahoo.com, ddloc at skku.edu > > > > > > -- > > > > ___ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum --- Stefano Baroni - SISSA & DEMOCRITOS National Simulation Center - Trieste http://stefano.baroni.me [+39] 040 3787 406 (tel) -528 (fax) / stefanobaroni (skype) La morale est une logique de l'action comme la logique est une morale de la pens?e - Jean Piaget Please, if possible, don't send me MS Word or PowerPoint attachments Why? See: http://www.gnu.org/philosophy/no-word-attachments.html -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20100615/04ca845a/attachment.htm
[Pw_forum] Computing Second order response
I don't understand why Raman activity in this case is zero. In practical, metallic system also provide Raman peak (ex. Carbon nannotube). I try to calculate graphene (no gap) and I get the proper result. Can you give some more explanation or suggest me some reference about this topic? I appreciate to your instructions. >So, the the Raman activity should be > zero ... >SB On Jun 15, 2010, at 3:50 AM, loc duong ding > wrote: > I calculate zigag nano ribbon with hydrogen terminated at the > edge. I checked DOS that showed no gap. > >> yes - SB > > > On Jun 14, 2010, at >>> 11:03 AM, loc duong ding > wrote: > >>> what's the gap of the >> unperturbed > >>> system? >>> SB >> >> Actually, > this >> is the firs time I calculate the Raman spectrum. I don't clear > about the gap of >> the unperturbed system? It means the electronic > band gap? --- Loc Duong Dinh Ms-Ph.D Student Sungkyunkwan Advanced Institute of Nanotechnology, Sungkyunkwan University, Suwon, 440-746, Korea Email: mambom1902 at yahoo.com, ddloc at skku.edu
[Pw_forum] Computing Second order response
I calculate zigag nano ribbon with hydrogen terminated at the edge. I checked DOS that showed no gap. > yes - SB On Jun 14, 2010, at >> 11:03 AM, loc duong ding wrote: >> what's the gap of the > unperturbed >> system? >> SB > > Actually, this > is the firs time I calculate the Raman spectrum. I don't clear about the gap > of > the unperturbed system? It means the electronic band gap? > > I > appreciate to your explanation. I am sorry about my late reply. > > > > >>> On May 31, 2010, at 6:10 PM, loc duong ding > >>> wrote: > >>> Dear all, >>> > >>> I want calculated IR and Raman of >>> nanoribbon. > The problem is when the code calcualtion second order response, it > >>> is not convergence. --- Loc Duong Dinh Ms-Ph.D Student Sungkyunkwan Advanced Institute of Nanotechnology, Sungkyunkwan University, Suwon, 440-746, Korea Email: mambom1902 at yahoo.com, ddloc at skku.edu --
[Pw_forum] Computing Second order response
yes - SB On Jun 14, 2010, at 11:03 AM, loc duong ding wrote: >> what's the gap of the unperturbed >> system? >> SB > > Actually, this is the firs time I calculate the Raman spectrum. I don't clear > about the gap of the unperturbed system? It means the electronic band gap? > > I appreciate to your explanation. I am sorry about my late reply. > > > >>> On May 31, 2010, at 6:10 PM, loc duong ding >>> wrote: > >>> Dear all, >>> >>> I want calculated IR and Raman of >>> nanoribbon. The problem is when the code calcualtion second order response, >>> it >>> is not convergence. >>> > --- > Loc Duong Dinh > Ms-Ph.D Student > Sungkyunkwan Advanced Institute of Nanotechnology, > Sungkyunkwan University, > Suwon, 440-746, Korea > Email: mambom1902 at yahoo.com, ddloc at skku.edu > > > > ___ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum --- Stefano Baroni - SISSA & DEMOCRITOS National Simulation Center - Trieste http://stefano.baroni.me [+39] 040 3787 406 (tel) -528 (fax) / stefanobaroni (skype) La morale est une logique de l'action comme la logique est une morale de la pens?e - Jean Piaget Please, if possible, don't send me MS Word or PowerPoint attachments Why? See: http://www.gnu.org/philosophy/no-word-attachments.html -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20100614/f3204378/attachment.htm
[Pw_forum] Computing Second order response
>what's the gap of the unperturbed > system? >SB Actually, this is the firs time I calculate the Raman spectrum. I don't clear about the gap of the unperturbed system? It means the electronic band gap? I appreciate to your explanation. I am sorry about my late reply. >>On May 31, 2010, at 6:10 PM, loc duong ding >> wrote: > >Dear all, > > > >I want calculated IR and Raman of > >nanoribbon. The problem is when the code calcualtion second order response, > >it > >is not convergence. >> --- Loc Duong Dinh Ms-Ph.D Student Sungkyunkwan Advanced Institute of Nanotechnology, Sungkyunkwan University, Suwon, 440-746, Korea Email: mambom1902 at yahoo.com, ddloc at skku.edu
[Pw_forum] Computing Second order response
what's the gap of the unperturbed system? SB On May 31, 2010, at 6:10 PM, loc duong ding wrote: > Dear all, > > I want calculated IR and Raman of nanoribbon. The problem is when the code > calcualtion second order response, it is not convergence. > > This is the output: > > > Calling punch_plot_e > Writing on file drho > > > > > Computing Pc [DH,Drho] |psi> > > Derivative coefficient: 0.001000Threshold: 1.00E-12 > Non-scf u_k: avg # of iterations = 23.5 > Non-scf Du_k: avg # of iterations = 37.6 > > Dielectric constant from finite-differences > > ( 1.626169126 -0.012354543 0.00672 ) > ( -0.012354543 1.773889718 -0.001492007 ) > ( 0.00672 -0.001492007 1.106263603 ) > > Computing Second order response > > > iter # 1 av.it.: 10.8 > thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.194E+04 > > > iter # 2 av.it.: 15.7 > thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.509E+09 > > > iter # 3 av.it.: 15.2 > thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.134E+07 > > > iter # 4 av.it.: 12.7 > thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.986E+03 > > > iter # 5 av.it.: 11.2 > thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.693E+01 > > > iter # 6 av.it.: 14.3 > thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.269E+04 > > > iter # 7 av.it.: 13.7 > thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.154E+02 > > > iter # 8 av.it.: 12.8 > thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.631E+01 > > > iter # 9 av.it.: 11.5 > thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.136E+00 > > > iter # 10 av.it.: 10.8 > thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.116E+02 > > > iter # 11 av.it.: 10.0 > thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.598E+00 > > > iter # 12 av.it.: 9.3 > thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.220E+00 > > > iter # 13 av.it.: 10.2 > thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.416E+01 > > > iter # 14 av.it.: 10.7 > thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.340E+00 > > > iter # 15 av.it.: 10.0 > thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.648E+01 > > > iter # 16 av.it.: 11.0 > thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.214E+02 > > > iter # 17 av.it.: 12.3 > thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.152E+03 > > > iter # 18 av.it.: 12.2 > thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.314E-01 > > > iter # 19 av.it.: 12.2 > thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.538E+02 > > > iter # 20 av.it.: 11.2 > thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.744E+01 > > > iter # 21 av.it.: 13.0 > thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.150E+04 > > > iter # 22 av.it.: 13.7 > thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.426E+03 > > > iter # 23 av.it.: 12.7 > thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.238E+03 > > > iter # 24 av.it.: 17.2 > thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.143E+07 > > > iter # 25 av.it.: 15.8 > thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.118E+06 > > > iter # 26 av.it.: 18.8 > thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.122E+08 > > > iter # 27 av.it.: 19.3 > thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.361E+07 > > > iter # 28 av.it.: 19.5 > thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.447E+08 > > > iter # 29 av.it.: 22.5 > thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.186E+11 > > > iter # 30 av.it.: 23.2 > thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.390E+10 > > > iter # 31 av.it.: 25.7 > thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.538E+12 > > > iter # 32 av.it.: 25.8 > thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.231E+12 > > > iter # 33 av.it.: 27.2 > thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.105E+14 > > > iter # 34 av.it.: 30.5 > thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.700E+15 > > > iter # 35 av.it.: 31.2 > thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.228E+15 > > > iter # 36 av.it.: 31.8 > thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|
[Pw_forum] Computing Second order response
On May 31, 2010, at 18:10 , loc duong ding wrote: > The problem is when the code calcualtion second order response, > it is not convergence. try to reduce "alpha_mix" to a smaller value, 0.3 or 0.1 or whatever is appropriate (default is 0.7) P. --- Paolo Giannozzi, Dept of Physics, University of Udine via delle Scienze 208, 33100 Udine, Italy Phone +39-0432-558216, fax +39-0432-558222
[Pw_forum] Computing Second order response
Dear all, I want calculated IR and Raman of nanoribbon. The problem is when the code calcualtion second order response, it is not convergence. This is the output: Calling punch_plot_e Writing on file drho Computing Pc [DH,Drho] |psi> Derivative coefficient: 0.001000Threshold: 1.00E-12 Non-scf u_k: avg # of iterations = 23.5 Non-scf Du_k: avg # of iterations = 37.6 Dielectric constant from finite-differences ( 1.626169126 -0.012354543 0.00672 ) ( -0.012354543 1.773889718 -0.001492007 ) ( 0.00672 -0.001492007 1.106263603 ) Computing Second order response iter # 1 av.it.: 10.8 thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.194E+04 iter # 2 av.it.: 15.7 thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.509E+09 iter # 3 av.it.: 15.2 thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.134E+07 iter # 4 av.it.: 12.7 thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.986E+03 iter # 5 av.it.: 11.2 thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.693E+01 iter # 6 av.it.: 14.3 thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.269E+04 iter # 7 av.it.: 13.7 thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.154E+02 iter # 8 av.it.: 12.8 thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.631E+01 iter # 9 av.it.: 11.5 thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.136E+00 iter # 10 av.it.: 10.8 thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.116E+02 iter # 11 av.it.: 10.0 thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.598E+00 iter # 12 av.it.: 9.3 thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.220E+00 iter # 13 av.it.: 10.2 thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.416E+01 iter # 14 av.it.: 10.7 thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.340E+00 iter # 15 av.it.: 10.0 thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.648E+01 iter # 16 av.it.: 11.0 thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.214E+02 iter # 17 av.it.: 12.3 thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.152E+03 iter # 18 av.it.: 12.2 thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.314E-01 iter # 19 av.it.: 12.2 thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.538E+02 iter # 20 av.it.: 11.2 thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.744E+01 iter # 21 av.it.: 13.0 thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.150E+04 iter # 22 av.it.: 13.7 thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.426E+03 iter # 23 av.it.: 12.7 thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.238E+03 iter # 24 av.it.: 17.2 thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.143E+07 iter # 25 av.it.: 15.8 thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.118E+06 iter # 26 av.it.: 18.8 thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.122E+08 iter # 27 av.it.: 19.3 thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.361E+07 iter # 28 av.it.: 19.5 thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.447E+08 iter # 29 av.it.: 22.5 thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.186E+11 iter # 30 av.it.: 23.2 thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.390E+10 iter # 31 av.it.: 25.7 thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.538E+12 iter # 32 av.it.: 25.8 thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.231E+12 iter # 33 av.it.: 27.2 thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.105E+14 iter # 34 av.it.: 30.5 thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.700E+15 iter # 35 av.it.: 31.2 thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.228E+15 iter # 36 av.it.: 31.8 thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.362E+17 iter # 37 av.it.: 34.0 thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.201E+17 iter # 38 av.it.: 35.8 thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.245E+19 iter # 39 av.it.: 38.2 thresh= 0.100E-01 alpha_mix = 0.700 |ddv_scf|^2 = 0.370E+20 iter # 40 av.it.: 37
