[gmx-users] g_helix question

[Zhen Qin]

hi,
 I met a problem when trying to analyse my system with g_helix function.
My system contains a protein (belta-helix), some membrane lipid molecules,
and a lot of water. I want to use g_helix to compute the helix properties,
so I use:
 g_helix -f history.xtc -s system.tpr -n index.ndx
(my index.ndx contains atoms that form the helix).

 However, after I ran, I found all the .xvg files excepting
JCaHa.xvg and helicity.xvg generated contains only
the informatic head, no data at all. And in helicity.xvg, the data part is
like
         1           0
         2           0
         3           0
         4           0
         5           0
         6           0
          ....
          ....

 and all the .out files are empty.

 This is my first time to use g_helix, I am totally confused. Are my input
files wrong? What shall I do?

 Thank you very much.


Yours
Zhen


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