Help Needed: Issue with Printing Group Atom Count to File in CFD-DEM LIGGGHTS Command

Submitted by fanyihui22 on Sat, 01/06/2024 - 14:53

Dear all,

We defined a group in LiggghtsCommand) , and then plan to print the total number of atoms in the group to a file.

executeProps0
{
command
(
group dele variable melt // melt was defined in liggghts
variable num equal count(dele)
print $num append noBlanks nummelt dot txt
);
runFirst off;
runLast off;
runEveryCouplingStep 1;
runEveryWriteStep off;
verbose;
}

But error occours. FOAM fatal IO error:
Illegal dictionary entry or environment variable name "num"
valid dictionary entries are 0( ).

if we changed to : print v_num append noBlanks nummelt dot txt
or print num append noBlanks nummelt dot txt
The nummelt.txt is generated, but every line is string "num" or "v_num"

Any comments are very appreciated.
regards,