Error running on multiple pprocessors

Dear lammps users,

I have a problem in running my file on multiple processors. When I try “mpirun -np 1 ./lmp_mpi -in in.myfile” I get no error. When I try using 2 processors, again I have no problem, but when increasing the np to 8 or 16, I get the following error:

ERROR on proc 0: Restrain atoms 36 25 28 30 missing on proc 0 at step 0 (…/fix_restrain.cpp:459)
application called MPI_Abort(MPI_COMM_WORLD, 1) - process 0
ERROR on proc 1: Restrain atoms 8356 8345 8348 8350 missing on proc 1 at step 0 (…/fix_restrain.cpp:459)
application called MPI_Abort(MPI_COMM_WORLD, 1) - process 1

I searched the error section of the manual and I found that it is relaed to dihedrals. But I don’t know why it happens only when I use more than 2 processors???
Anyone can help with finding where the problem could be?

Thanks.

Neda

Dear lammps users,
I have a problem in running my file on multiple processors. When I try
"mpirun -np 1 ./lmp_mpi -in in.myfile" I get no error. When I try using 2
processors, again I have no problem, but when increasing the np to 8 or 16,
I get the following error:

ERROR on proc 0: Restrain atoms 36 25 28 30 missing on proc 0 at step 0
(../fix_restrain.cpp:459)
application called MPI_Abort(MPI_COMM_WORLD, 1) - process 0
ERROR on proc 1: Restrain atoms 8356 8345 8348 8350 missing on proc 1 at
step 0 (../fix_restrain.cpp:459)
application called MPI_Abort(MPI_COMM_WORLD, 1) - process 1

I searched the error section of the manual and I found that it is relaed
to dihedrals. But I don't know why it happens only when I use more than 2
processors???

​because your domain decomposition subdomains are ​too small to contain all
atoms listed in the restraint. you may have to increase your communication
cutoff or check whether the restrain selection is correct.

axel.

Thanks Axel,

But when I increase my lj and coloumbic cut offs from 10 and 12 angstrom to 12 and 14 , I get another error “neighbour list overflow”

How can I solve this problem? How can I get a sense of values that should be defined in neighbour and neighbour_modify commands?

Thanks

Neda

Thanks Axel,
But when I increase my lj and coloumbic cut offs from 10 and 12 angstrom
to 12 and 14 , I get another error "neighbour list overflow"

​communication cutoff != interaction cutoff.​

How can I solve this problem? How can I get a sense of values that should

be defined in neighbour and neighbour_modify commands?

​you need to spend more time reading the documentation and also need to
spend more attention to detail.​

​it is quite suspicious, that you get a neighbor list overflow with 14
angstrom cutoff. you either have an unusual system or a bad geometry.

axel.​