VASP.md

@@ -12,8 +12,10 @@ bash$ ls /software/user_tools/current/cades-cnms/pbs_samples
 
 Note if you are batching jobs you need to look at the example for that.  It does not work like at NERSC
 
-for example you have 512 cores allocated
+The most robust option is to give each mpirun in your job its own pbs nodefile to work with and pay attention to the binding and mapping you are using, there is an example in the repo like this.
 
+More simply this mpirun idiom should work but you need to be careful and check it in an interactive job first.
+for example you have 512 cores allocated
 to run three separate batch jobs
 ```shell_session
 bash$ mpirun -x OMP_NUM_THREADS=1 --mca btl self,sm,openib --map-by slot:SPAN --bind-to core