[Pw_forum] Solved! Re: Problems running PWscf in parallel

[Paolo Giannozzi]

On Tuesday 01 November 2005 22:06, stewart at cnf.cornell.edu wrote:

> Marco Fornari suggested changing the following three lines of f_def.h
> in the include directory from
>
> #if defined(__LAM) && ( defined (__LINUX) || defined (__LINUX64) )
> #define MPI_REAL8 MPI_DOUBLE_PRECISION
> #endif
>
> to
>
> #if defined(__LAM) || ( defined (__LINUX) || defined (__LINUX64) )
> #define MPI_REAL8 MPI_DOUBLE_PRECISION
> #endif

I don't see the difference: if you have a Linux PC, either a 32- or a 64-bit
machine, and if you #define __LAM, in both cases you have the same result
(i.e. redefine  MPI_REAL8, which some implementation of LAM don't like,
to MPI_DOUBLE_PRECISION). If you don't define __LAM you may have a 
different result, but this is exactly why __LAM is there and why it should
be #define'd if needed

> This change might be a good thing to implement in the next version
> of the espresso package. 

it would break other cases, for sure

Paolo

-- 
Paolo Giannozzi             e-mail:  giannozz at nest.sns.it
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