compute chunk and fix ave/chunk

Dear lammps users,

I’m using Lammps 12 dec 2018. I breefly explain my issue, the complete input file is attached.

I define
group waterOx type 1

variable Nadaptw equal 1000 # every 1000 fs averages
variable Neveryw equal 10 # every 10 fs, take a sample
variable Nrepeatw equal 100 # do it 100 times

compute compdens waterOx chunk/atom bin/1d z lower 0.1 units box
fix densityc waterOx ave/chunk {Neveryw} {Nrepeatw} ${Nadaptw} compdens density/number density/mass file density_PFDA_60_40_mod.profile

run 1000

unfix densityc

However the output is only:

Chunk-averaged data for fix densityc and group density/mass

Timestep Number-of-chunks Total-count

Chunk Coord1 Ncount density/number density/mass

without any additional info. This seems very strange since i have used the same lines in other scripts and everything went fine.

Do you have any suggestions about what might cause this problem?

Kind regards,

density_PFDA_60_40_mod.profile (152 Bytes)

in_PFDA_60_40_slab_mod.gro2lam (8.69 KB)

fix ave/chunk will start collecting and output data on timesteps divisible by 1000 with your current settings. if your current timestep is not divisible by 1000, then it will take more than 1000 steps to see some output. typically, this kind of thing can be remedied by adding a reset_timestep 0 command before issuing fix ave/XXX commands.


I checked and that was the issue, my bad since i was trying with random timesteps numbers since my server for the runs is not available and also just after the 1000 timesteps i was resetting the timesteps for FEP, so it stopped averaging after also.

Thank you for the prompt answer!