Script to determine Processes per node (PPN)

Hi,

I am running lattice configurtaion 8x8x8x8x8.chklat and  18x18x18x36.chklat on 6 nodes having max PPN=48. Some of the configurations either hang after warmup iterations are completed or show "not enough factors of 5/7/11/23" etc. 

Do you have a script to determine what PPN can be specified for a given lattice configuration and node count?

Thanks,
Amit Ruhela