I have successfully used fix tmd to perform a targeted Molecular Dynamics in order to evaluate the work needed to extract a CS2 molecule from a nanocage of C50H10 back in 2012. Since then I have upgraded our lamps version and now I have in our machines both a version from Nov. 2014 and a later one from April 2015. With these new versions the simulation now hangs up for ever when reading the Target structure file !! nothing has changed in my files, so I asume there must be some change in lammps itself, but the documentation has no indication whatsoever ! Unfortunately I no longer have access to the old binary. Any help would be appreciated
There must have been quite a few changes to LAMMPS over the past three years. My suggestion is read the current fix tmd doc page thoroughly, compare it against your input script, and figure out what changes to your input script are necessary.