[Pw_forum] relaxation problem on IBM bluegene machine

[Paolo Giannozzi]

On Jan 5, 2009, at 23:50 , pushpa raghani wrote:

> I am doing slab relaxation (surface) calculations on IBM bluegene  
> machine.
> For certain cell sizes, the calculations go very fine but for some  
> others, it
> stops after doing  the first scf run and then calculating forces  
> and the new
> atomic positions, ie, it stops while 'Writing output data file  
> pwscf.save'. The
> status shows that the calculation is running but it doesn't do  
> anything. Could
> somebody tell me why does it this happen and how can it be fixed?

short answer: no, nobody can. You have to discover what happens exactly
and under which circumstances: if this is blue-gene specific or not,  
if it is
reproducible or erratic, what happens if you change options (try to keep
data into memory instead of saving them to file), etc. etc.. It looks  
to me
like a problem in the file system, or in its usage, rather than in  
quantum
espresso itself.

> I am using 3.2.3 version.

you should use more recent versions. They better support bluegene  
machines
and have a better scalability. Not sure this will do anything to fix  
your problem,
though

Paolo
---
Paolo Giannozzi, Democritos and University of Udine, Italy