[lammps-users] Question on use of fix ave/spatial

      I am trying to use fix ave/spatial on a polymer system. When i
try to run the program it pops up with the following error

ERROR: Use of fix ave/spatial with undefined lattice

I was expecting that the lattice prameters will be read from the data
file but it does not seem so. I also tried adding lattice custom
command to mention the lattice parameter values but it also needs some
basis atoms which in the case of polymer system is inapproriate and so
are other lattice commands as it seems to me. I would apreciate if
there is workaround or, is it that fix ave/spatial can't be used with
these kind of amorphous systems.


There are no lattice parameters in a data file. They are
only defined via the lattice command. If you don't want
to use lattice units for the fix ave/spatial, then append
"units box" to the command, as it's doc page discusses.
Then your bin size will be in Angstroms (or whatever).