[gmx-users] Calculating tilt angle with respect to the membrane normal

[zeineb SI CHAIB]

Finally, I visualized the data in the output file of -otilt  (tilt_TMC1CA.xvg) using xmgrace with the command: xmgrace -nxy tilt_TMC1CA.xvg

I read again the documentation of gmx helixorient and if I understood well, the values of the tilt angle of the helix axis to the membrane plan are reported in the file theta2.xvg. Is it correct?

Also, the values of the tilt angle are supposed to be within the range [0-90] deg (if I understood well)  but in my graphs, I am getting negative values?!

Again, I would really appreciate your help, please to interpret the results of gmx helixorient. I tried to read the documentation/forums but things are still not clear to me.