[gmx-users] g_energy=> Different Average values?

[Chih-Ying Lin]

Hi
I have read through the manual but could not get it.
Would you please explain it more?



Thank you

Lin


Chih-Ying Lin wrote:
>
>
> Hi
> After the command,
> g_energy  -f abc.edr -o abc.xvg
>
> the average values is printed out on the screen.
> Energy
>       Average         RMSD    Fluct.  Drift   Tot-Drift
> Potential
>       -267323         375.096         374.647         -0.12711        -63.5543
> Kinetic       En.     51901.5         259.034         259.015         -0.02151        -10.7574
> Total         Energy  -215421         275.52  274.683         -0.14862        -74.3106
> Temperature   302.825         1.51136         1.51125         -0.00013        -0.06277
> Pressure      (bar)   0.963727        133.498         133.335         0.045602        22.8012
> Volume
>       221.643         0.362625        0.362424        8.36E-05        0.041823
> Density       (SI)    990.272         1.62111         1.6202  -0.00038        -0.18852
>
>
>
>
> but the average values are different than calculation from the
> instantaneous data in the  abc.xvg
>
> I sum up all the instantaneous data in the abc.xvg and average them.
> I got different average data as those shown up on the screen after
> g_energy command.

The average values reported in the .edr file are not necessarily the
averages of the values in the .edr file. See manual appendix.

Mark