[Wien] Is it possible to use a local scratch directory when (# of k-points)/( of nodes) != integer?

[Steven Hahn]

Dear WIEN2k users and developers,

I am having trouble running WIEN2k calculations on our cluster when  
the number of k-points produced by "x kgen" does not have a  
reasonable factor to use for the number of processes. For example,  
with 246 k-points I'd like to be able to use more than 6 cores, but  
the calculation isn't large enough to efficiently use 41 cores. Even  
if the load balancing is no longer perfect, the calculation could  
still be completed much faster with 13 or 19 cores. Also, I prefer  
running with four processes per nodes so that my lapw1 and lapw2  
processes are not scattered amongst the nodes in the cluster. The  
home directory is too slow to consider using for scratch. Everything  
I've tried so far has produced intermittent errors like "forrtl:  
severe (24): end-of-file during read, unit 10, file /var/scratch/ 
shahn/case_1/case_1.vector_16" in lapw2. Once I realized the problem  
is because the (# of k-points)/( of nodes) != integer, I have tried:

1) removing extrafine:1 from my PBS script. The calculation still  
crashes occasionally because the residual k-points are not always  
running on the same node. I got the misconception that extrafine:1 is  
compatible with granularity:1 and a local scratch disk from the  
example PBS script (http://www.wien2k.at/reg_user/faq/pbs.job).  
Should the extrafine:1 line be removed from the example?

2) replacing one line in my .machines file with residue:(name of  
node). I'm not sure why this is failing. Testpara_lapw shows only one  
list of k-points for each core.

Before I start modifying scripts, I was wondering if it is possible  
to still use the existing scripts, a local scratch directory, and  
overcome the  (# of k-points)/( of nodes) = integer requirement? Is  
this limitation just in the lapwpara_lapw1 and lapwpara_lapw2  
scripts, or is there a more fundamental concern? Would others be  
interested in being able to run with any number of processes?

Sincerely,
Steven Hahn