The analysis module can convert NWChem trj files into Amber crd, Discover arc or Charmm dcd files. See the 'copy' directive in the trajectory file conversion section. Individual frames out of a trajectory can be converted into pdb or xyz format using the 'write' directive.
Yeah, I tried that and it is broken.
Error is: "Unresolved atom types in fragment w5" when I run a simulation with 5 H2Os in it.