<html><body><div style="color:#000; background-color:#fff; font-family:times new roman, new york, times, serif;font-size:12pt"><div>Dear GROMACS Specialists,<br><br>I have one question about radius of gyration for micelle, Please help me.<br>My micelle is created at 100000 ps by Martini CG force field.<br>When I calculate the radius of gyration from this time as "g_gyrate -f 1.xtc -s 1.tpr -n 1.ndx -o gyrate.xvg -b 100000" and "g_analyze -f gyrate.xvg -av -ee", my answer is:<br><br> std. dev. relative deviation of<br> standard ---------
cumulants from those of<br>set average deviation sqrt(n-1) a Gaussian distribition<br> cum. 3 cum. 4<br>SS1 1.811581e+00 1.586248e-02 3.708049e-05 0.399 0.318<br>SS2 1.476027e+00 5.355297e-02 1.251867e-04 0.009 -0.039<br>SS3 1.480446e+00 5.226397e-02 1.221735e-04 0.004
-0.060<br>SS4 1.478287e+00 5.332558e-02 1.246551e-04 -0.005 -0.084<br><br>Set 1: err.est. 0.000281889 a 0.468124 tau1 20.1606 tau2 308.225<br>Set 2: err.est. 0.0024333 a 0.925872 tau1 536.208 tau2 8592.94<br>Set 3: err.est. 0.00190226 a 0.971916 tau1 544.756 tau2 7044.58<br>Set 4: err.est. 0.00267771 a 0.991392 tau1 629.613 tau2 88302<br><br>But when I calculate it from start time of simulation as "g_gyrate -f 1.xtc -s 1.tpr -n 1.ndx -o gyrate.xvg" and "g_analyze -f gyrate.xvg -av -ee", my answer is:<br><br> std.
dev. relative deviation of<br> standard --------- cumulants from those of<br>set average deviation sqrt(n-1) a Gaussian distribition<br> cum. 3 cum. 4<br>SS1 1.979407e+00 6.228274e-01 1.392685e-03 2.317 4.169<br>SS2
1.613785e+00 5.401095e-01 1.207722e-03 2.478 4.949<br>SS3 1.601265e+00 4.713569e-01 1.053986e-03 2.547 5.460<br>SS4 1.624623e+00 5.387790e-01 1.204746e-03 2.208 3.719<br><br>Warning: tau2 is longer than the length of the data (1.2e+06)<br> the statistics might be bad<br>invalid fit: e.e. -nan a 5.56656 tau1 674505 tau2 8.75077e+07<br>Will fix tau2 at the total time: 1.2e+06<br>a fitted parameter is negative<br>invalid fit: e.e. -nan a 18.789 tau1 806548 tau2 1.2e+06<br>Will use a single exponential fit for set 1<br>Set 1: err.est. 0.212562 a 1 tau1 69885.8 tau2 0<br>a
fitted parameter is negative<br>invalid fit: e.e. 20.1017 a 2.22647 tau1 210523 tau2 -6.77257e+08<br>Will fix tau2 at the total time: 1.2e+06<br>a fitted parameter is negative<br>invalid fit: e.e. -nan a 3.04296 tau1 249121 tau2 1.2e+06<br>Will use a single exponential fit for set 2<br>Set 2: err.est. 0.170009 a 1 tau1 59447.7 tau2 0<br>a fitted parameter is negative<br>invalid fit: e.e. 0.139564 a 1.61177 tau1 36947.7 tau2 11359.6<br>Will fix tau2 at the total time: 1.2e+06<br>a fitted parameter is negative<br>invalid fit: e.e. -nan a 2.35981 tau1 195092 tau2 1.2e+06<br>Will use a single exponential fit for set 3<br>Set 3: err.est. 0.149959 a 1 tau1 60729.6 tau2 0<br>a fitted parameter is negative<br>invalid fit: e.e. 6.4854 a 5.92085 tau1 759910 tau2
-1.67528e+07<br>Will fix tau2 at the total time: 1.2e+06<br>a fitted parameter is negative<br>invalid fit: e.e. -nan a 30.0389 tau1 922726 tau2 1.2e+06<br>Will use a single exponential fit for set 4<br>Set 4: err.est. 0.184771 a 1 tau1 70566.6 tau2 0<br><br>and my plot of errest.xvg in the first one is similar with article "B. Hess, J. Chem. Phys. 116:209-217, 2002" but in the second one is different whereas err.est in second are similar to micellar articles.<br><br>I don't know which one is true, time of simulation start or time of creation of micelle?<br><br>Both of them (the radius of gyration) is in agreement with experimental but second one is more near than first one.<br><br>Please help me.<br>Thank you very much in advance.<br>Best Regards<br>Dina<br><br><br><br></div></div></body></html>