optistruct parallel job on multi node

Hi,

I have installed optistruct solver on cluster. I have 4 nodes in cluster and each node have 32 cpus.

I want to run optistruct analysis job via command line on linux system.

 

/gscratch/apps/hwsolvers/altair/scripts/optistruct  input_file.fem -nproc 64 &

 

the job is running on only 32 cpus not on 64 cpus.

please let me know what options i need to place on command line to run on multiple nodes.