[lammps-users] fix shake error that appears by the new version of LAMMPS

Dear LAMMPS users,

Hi.
I tried to use a restart file from an old LAMMPS package (lammps-3Mar20) to the new version (lammps-29Sep2021) but I got an error message regarding to the “fix shake” command:

ERROR: Shake cluster of more than 4 atoms (…/fix_shake.cpp:868)

When I use old versions of LAMMPS this error disappears!

Can you please let me know what the problem is?

Best,
Saeed.

This might be a more fundamental problem with reading the restart file, if the format has changed.
I suggest converting the restart file to a date file (with the old version). Then read the data
file with the new version, apply your SHAKE fix in your new script, etc.

Steve