[gmx-users] problem in g_density

[cdalgicdir]

Hi,

The simulation box consists of layers of cyclohexane and vacuum. 
Ensemble is NVT.

The density profiles of cyclohexane for 5-10 ns, 10-15 ns and 15-20 ns 
coincide. However the density profile for 5-20 ns is significantly 
higher than the ones calculated.
g_density -n -b 5000 -e 20000

If I calculate the 5-20 ns interval using every 5th frame the density 
profile resembles that of the 5-10, 10-15, 15-20 ns's.
g_density -n -b 5000 -e 20000 -dt 5

Attached is the graph of these profiles.

I have tried this in 4.07, 4.5.3 and 4.5.4. The results are similar for 
all these versions.

I am aware that such inconsistencies may occur with g_density in NPT 
ensembles. However I am using a NVT ensemble. Is there something am I 
missing? And more importantly,  how should I decide which one is the 
correct density?

Thanks,
Cahit
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