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 -0.00010. 0.0.7298
2 0.000.0. 0.0.4596
3 0.000.0. 0.0.3769
4 72.482.17280.2093 0.0.7221
5181.805.45030. 1725.78320.7500
6216.896.50230. 2083.45000.7500
7363.65 10.90210. 91729.50390.2795
8396.95 11.90010.104976.37800.7500
9420.27 12.59920. 0.0.6389
10425.05 12.74270. 1248.54190.7500
11451.38 13.53210.329620.46540.3306
12460.15 13.79490.1942 0.0.3225
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==UTF-8==es=en
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