Hi, save the data in a file, let's name it archive.dat call gnuplot with the command of the same name. Inside the gnuplot terminal, plot "archive.dat" using 2:5 with impulses or plot "archive.dat" u 2:5 w i
that will produce a plot of vertical lines. If you want a continuous curve, you need to write your own program. I know no utility in Quantum ESRESSO to do that. Any user of Quantum ESPRESSO and similar non-commercial packages needs to write, and enjoy doing it :-), some small programs to analize the output data. Yoy have asked for a GGA pseudopotential, but take into account that the PHONON code calculates the Raman spectra only for LDA and norm conserving pseudopotentials. I guess that vdW interaction is important for soft modes, or at least to have an apropriate strucuture with minimal energy, otherwise there are imaginary frequencies. Graphene is a famous case where vdW is important. best regards Eduardo Menendez Proupin Departamento de Qu?mica Fisica Aplicada Facultad de Ciencias Universidad Aut?noma de Madrid 28049 Madrid, Spain Phone: +34 91 497 6706 ---------- Mensaje reenviado ---------- From: Kondaiah Samudrala <konda.phys...@gmail.com> To: pw_forum at pwscf.org Cc: Date: Mon, 23 Jan 2012 15:45:23 +0530 Subject: [Pw_forum] Regarding raman spectra Dear all, I get the result of cross section of Raman and IR. The results are: # mode [cm-1] [THz] IR Raman depol 1 0.00 -0.0001 0.0000 0.0000 0.7298 2 0.00 0.0000 0.0000 0.0000 0.4596 3 0.00 0.0000 0.0000 0.0000 0.3769 4 72.48 2.1728 0.2093 0.0000 0.7221 5 181.80 5.4503 0.0000 1725.7832 0.7500 6 216.89 6.5023 0.0000 2083.4500 0.7500 7 363.65 10.9021 0.0000 91729.5039 0.2795 8 396.95 11.9001 0.0000 104976.3780 0.7500 9 420.27 12.5992 0.0000 0.0000 0.6389 10 425.05 12.7427 0.0000 1248.5419 0.7500 11 451.38 13.5321 0.0000 329620.4654 0.3306 12 460.15 13.7949 0.1942 0.0000 0.3225 The result of raman data are very well compared with the experimental result. But I am not able to plot Raman spectrum with this o/p using XMGRACE. Please give me suggetion for plot raman spectra. Here with i attached direct plot of my trail with xmgrace (2 and 5th colums) . What is the meaning of cross section in this calculation? Please provide norm conserving pseudopotential for phosphorus using GGA (PBE or PW91) XC-functional ( Using LDA-CAPZ is already in website). Finally, for structural properties semiemperical correction of Vdw interactions plays very importent role. But, Is there any influence of semiemperical correction to Vdw interaction on vibrational properties???? . I appreciate to all your instructions. with regards S.Appalakondaiah Research Schloar University of hyderabad Hyderabad India -- On leave from: Departamento de Fisica, Facultad de Ciencias, Universidad de Chile URL: http://fisica.ciencias.uchile.cl/~emenendez "*Padece, espera y trabaja para gentes que nunca conocer? y que a su vez padecer?n, esperar?n y trabajar?n para otros, que tampoco ser?n felices, pues el hombre ans?a siempre una felicidad situada m?s all? de la porci?n que le es otorgada. Pero la grandeza del hombre est? precisamente en querer mejorar lo que es. En imponerse Tareas. En el Reino de los Cielos no hay grandeza que conquistar, puesto que all? todo es jerarqu?a establecida, inc?gnita despejada, existir sin t?rmino, imposibilidad de sacrificio, reposo y deleite. Por ello, agobiado de penas y de Tareas, hermoso dentro de su miseria, capaz de amar en medio de las plagas, el hombre puede hallar su grandeza, su m?xima medida en el Reino de este Mundo*". Alejo Carpentier, El reino de este mundo, (1949). Translate from spanish here http://translate.google.com/?hl=&ie=UTF-8&text=&sl=es&tl=en -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20120124/db9741e2/attachment-0001.htm