A confusion about read_dump command

Dear,
After running a script, I output the dump file (dump.txt), including “id mol type x y z vx vy vz”
Then, I want to compute the energy of snaphots using a different potential (BNCH.ILP). Part of the script is as follows:

the atom attribute "molecule" is set with the atom style. if your atom
style does not support storing molecule ids, then read_dump cannot
assign them.

axel.