Thanks for reply. Still I have a question why it is -inf (infinity) at the end.
Nilesh > Hi, > > I would say the problem is too less statistics. In the paper where the > tool > was introduced, a simulation of 100ns has been performed in order to > achieved sufficient sampling. > > The order of magnitude is given due to the units. > > Simulate for a longer time to get rid of the noise. Calculating these kind > of correlations functions is really not a simple task. > > Schroeder et al. have published an article about fitting of dielectric > spectra for ionic liquids, where this problem is discussed in detail. > > Cheers, > Flo > >> -----Original Message----- >> From: gmx-users-boun...@gromacs.org [mailto:gmx-users- >> boun...@gromacs.org] On Behalf Of Nilesh Dhumal >> Sent: Monday, July 08, 2013 10:32 PM >> To: gmx-users@gromacs.org >> Subject: [gmx-users] g_current >> >> Hello, >> I am calculating the correlation of rotational and translation dipole >> moment of ionic liquids. I run the 1 ns simulation and saved the >> trajectory at 1 fs. >> >> g_current -f md.trr -s md.tpr -n index.ndx -mc >> >> I selected "system" group. >> >> Here I pasted the initial j(t) vales and the final value is infinity. >> >> # This file was created Sun Jul 7 20:51:59 2013 >> # by the following command: >> # g_current -f md.trr -s md.tpr -e 10.0 -mc >> # >> # g_current is part of G R O M A C S: >> # >> # Gallium Rubidium Oxygen Manganese Argon Carbon Silicon >> # >> @ title "M\sD\N - current autocorrelation function" >> @ xaxis label "Time (ps)" >> @ yaxis label "< M\sD\N (0)\c7\CJ(t) > (e nm/ps)\S2" >> @TYPE xy >> # time M_D(0) J(t) acf Integral acf >> 0.000 -5.20584e-15 0 >> 0.001 -6.97466e-15 -1.42702e-17 >> 0.002 -6.97511e-15 -5.25081e-17 >> 0.003 -6.97474e-15 -9.07484e-17 >> 0.004 -6.97391e-15 -1.28987e-16 >> >> >> >> Why final value is infinity? If I do autocorrelation function of these >> values, I get all values 0. >> >> Why J(t)values are in range of e-15? >> >> Nilesh >> >> >> >> -- >> gmx-users mailing list gmx-users@gromacs.org >> http://lists.gromacs.org/mailman/listinfo/gmx-users >> * Please search the archive at >> http://www.gromacs.org/Support/Mailing_Lists/Search before posting! >> * Please don't post (un)subscribe requests to the list. Use the >> www interface or send it to gmx-users-requ...@gromacs.org. >> * Can't post? Read http://www.gromacs.org/Support/Mailing_Lists > > -- > gmx-users mailing list gmx-users@gromacs.org > http://lists.gromacs.org/mailman/listinfo/gmx-users > * Please search the archive at > http://www.gromacs.org/Support/Mailing_Lists/Search before posting! > * Please don't post (un)subscribe requests to the list. Use the > www interface or send it to gmx-users-requ...@gromacs.org. > * Can't post? Read http://www.gromacs.org/Support/Mailing_Lists > -- gmx-users mailing list gmx-users@gromacs.org http://lists.gromacs.org/mailman/listinfo/gmx-users * Please search the archive at http://www.gromacs.org/Support/Mailing_Lists/Search before posting! * Please don't post (un)subscribe requests to the list. Use the www interface or send it to gmx-users-requ...@gromacs.org. * Can't post? Read http://www.gromacs.org/Support/Mailing_Lists
