last_frame.xmol
to preserve names of the atoms and also to help opening the XTC-file in VMD. The time and box size are read from the second (comment) line of every frame. If only step-number is provided (as in LAMMPS xyz-file), it will be used as time in fs.
> xmol2xtc trajectory.xmol
$MAGIC/CGTraj
folder and run make xmol2xtc