[Pw_forum] espresso3.0 different results in serial and paralelle mode...

[Cyrille Barreteau]

Dear PWscf fans,

I am facing a strange problem with pwscf (pw.x) of the
espresso3.0 version. I have performed two identical calculations:
one on my local linux machine and the same job on a linux cluster.
The compiler is the same (ifort version 9) and the machines are rather
similar (64bytes processors).
However the results are not exactly the same (see below
the result of calculations on Fe bcc and Fe wire from
serial and parallel executions..)

Any comment is very welcome

   cyrille

==================================================================
Fe bulk bcc:


  serial
     the Fermi energy is    12.4997 ev

!    total energy              =   -61.13842278 ryd
     estimated scf accuracy    <        8.9E-10 ryd

     band energy sum           =     6.08329685 ryd
     one-electron contribution =     3.42413935 ryd
     hartree contribution      =     8.76962528 ryd
     xc contribution           =   -30.38754311 ryd
     ewald contribution        =   -42.94464676 ryd
     correction for metals     =     0.00000247 ryd

     convergence has been achieved

  cluster
     the Fermi energy is    12.4997 ev

!    total energy              =   -61.13842278 ryd
     estimated scf accuracy    <        8.9E-10 ryd

     band energy sum           =     6.08329678 ryd
     one-electron contribution =     3.42413925 ryd
     hartree contribution      =     8.76962544 ryd
     xc contribution           =   -30.38754318 ryd
     ewald contribution        =   -42.94464676 ryd
     correction for metals     =     0.00000247 ryd

     convergence has been achieved
==================================================================
Fe wire


serial
     the Fermi energy is    -3.7064 ev

!    total energy              =   -60.94621023 ryd
     estimated scf accuracy    <        9.9E-09 ryd

     band energy sum           =    -3.47102873 ryd
     one-electron contribution =  -103.24843460 ryd
     hartree contribution      =    57.38042984 ryd
     xc contribution           =   -30.44155502 ryd
     ewald contribution        =    15.36351010 ryd
     correction for metals     =    -0.00016054 ryd

     total magnetization       =     3.33 Bohr mag/cell
     absolute magnetization    =     3.35 Bohr mag/cell

     convergence has been achieved


cluster

     the Fermi energy is    -3.7058 ev

!    total energy              =   -60.94621063 ryd
     estimated scf accuracy    <        3.3E-09 ryd

     band energy sum           =    -3.47080039 ryd
     one-electron contribution =  -103.24792049 ryd
     hartree contribution      =    57.37977246 ryd
     xc contribution           =   -30.44141187 ryd
     ewald contribution        =    15.36351010 ryd
     correction for metals     =    -0.00016084 ryd

     total magnetization       =     3.33 Bohr mag/cell
     absolute magnetization    =     3.35 Bohr mag/cell

     convergence has been achieved


-- 
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Cyrille Barreteau  | phone : +33 (0)1 69 08 29 51
CEA Saclay         | fax   : +33 (0)1 69 08 84 46
DSM/DRECAM/SPCSI   | email : cyrille.barreteau at cea.fr
Batiment 462       |
91191 Gif sur Yvette Cedex  FRANCE
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