[lammps-users] Help for dump file.

Dear Users,

I saved restart file and run the simulation with restart file by reading reading the file.
My question is :
I want to write the trajectory file including the previous file.
I realized that the previous dump.dcd file is erased after running the restart file.

previous dump.dcd file 0ns to 2ns.
new dump.dcd file 2ns to 4ns.

So, newly generaged dump.dcd file erases the data from 0 ns to 2ns.

How can i add 2ns-4ns to 0ns-2ns ?
I want the new dump.file to cover 0ns - 4ns ?
Could you please tell me what to do ?

Thank you a lot.

When you restart a run, LAMMPS can't regenerate dump
snapshots for time before the restart. That info doesn't exist.
So change the name of the dump file in the restart run
and you will have 2 dump files (the 1st one won't be erased).
I don't know if you can do this with DCD files, but

cat file1 file > fileboth

would work for other dump formats to create a single file
after the fact.