problem in running lammps in parallel

Dear all,
I have recently install lammps in parallel (with ubuntu 11.10 and intel core i5 (4 processors)) and get an executable lmp_ubuntu, when i try the command

./lmp-ununtu <in.file
It works fine
but i want to run lammps in parallel thats why i use command
mpirun −np 4 lmp_ubuntu -in testcuzr
or
mpirun −np 4 lmp_ubuntu <testcuzr
An error apears
[proxy:0:[email protected]…1531…] HYDU_create_process (./utils/launch/launch.c:69): execvp error on file −np (No such file or directory)

what is actually wrong? Can any body helps me about this problem?
Thanks and regards
Imran

Dear all,
              I have recently install lammps in parallel (with ubuntu 11.10 and intel core i5 (4 processors)) and get an executable lmp_ubuntu, when i try the command

              ./lmp-ununtu <in.file
It works fine
but i want to run lammps in parallel thats why i use command
mpirun −np 4 lmp_ubuntu -in testcuzr
or
mpirun −np 4 lmp_ubuntu <testcuzr
An error apears
[proxy:0:[email protected]] HYDU_create_process (./utils/launch/launch.c:69): execvp error on file −np (No such file or directory)

what is actually wrong? Can any

This is not a lammps problem but an "I have no clue how to use MPI problem".

The error is produced by mpirun and not lammps. Compile and run an MPI test or example program and see.

Axel

you should provide complete address for non-system executable files with mpirun too. i.e use this:

mpirun -np 4 ./lmp_ubuntu <in.file

instead of this:

mpirun -np 4 lmp_ubuntu <in.file