[gmx-users] Understanding g_energy output in GROMACS 4.5.7

[Agnivo Gosai]

Dear Users

This is the output of g_energy command on the em.edr file for my system. I
ran a preliminary energy minimization following the solvation and ions
addition of my system.

Last energy frame read 855 time 1080.000

Statistics over 1081 steps [ 0.0000 through 1080.0000 ps ], 1 data sets
All statistics are over 856 points (frames)

Energy                      Average   Err.Est.       RMSD  Tot-Drift
-------------------------------------------------------------------------------
Potential                   -685672      22000    69839.9    -138494
(kJ/mol)

I am unable to understand the meaning of the term "Err. Est" and
"Tot-drift". I have consulted the GROMACS manual but I am not satisfied and
failed to understand the physical significance.

Kindly explain.

Thanks & Regards

Agnivo Gosai
Grad. Student, ISU