[gmx-users] Question about "gmx traj" command

[Chang Woon Jang]

Dear Gromacs Users,

    I have a question about the gmx traj in order to calculate the force
components.

I used the following command. > gmx traj -f topol_new.trr -s topol_new.tpr
-af force_all_z_l9.xvg -z yes

It produced "force_all_z_l9.xvg" file. In the file, there are four columns.
The first column should be the atom ID.

My question is what is the rest of columns? For example, some of the values
are negative and the other values are positive.

-z yes means the plot of Z-component in the manual. I do not know what the
exact meaning of three columns. Would you please give me a comment on that?

Thank you.


# This file was created Mon Oct 16 21:53:33 2017
# Created by:
#        :-) GROMACS - gmx traj, 2016.4-dev-20170620-8d2584c-unknown (-:
#
# Executable:  /home/chang/Packages/votca/bin/gmx
# Data prefix:  /home/chang/Packages/votca
# Working dir:  /home/chang/2017_NU_PROJECT/1_FIRST_PROJECT/1_Less_5Million/
5_REVERSED_ATOMISTIC_TEST/1_Lambda_9/1_TENSION/1_SR10e8_l9_
300K/ANALYSIS/7_Force_Component
# Command line:
#  gmx traj -f topol_new.trr -s topol_new.tpr -af force_all_z_l9.xvg -z yes
# gmx traj is part of G R O M A C S:
#
# Gromacs Runs One Microsecond At Cannonball Speeds
#
@    title "average force"
@    xaxis  label "Atom"
@    yaxis  label "Spatial component"
@TYPE xy
1        -11.866      42.002      29.565
2          22.660    -11.028    -21.749
3          -0.232      -3.681      4.181
4          -9.308    -31.931    -22.545
5        -27.221    -21.572      7.099
6          11.648      4.523      -8.757
7          32.491      0.888      17.891


Best regards,
Changwoon Jang