[Pw_forum] problem about the calculation of the Raman tensor

[li yan]

dear all,
     I calcultated the Raman tensor  using the pwscf version 3.0. The scf part run correctly. But the the running of the ph.x will stop unexpectedly. The fowllowing part is the ph.out.
   
   Program PHONON    v.3.0    starts ...
     Today is 26Mar2006 at  0:46:20 
       Ultrasoft (Vanderbilt) Pseudopotentials
       Reading file SnO.save ...      only dimensions
     read complete
       Reading file SnO.save ...      all except wavefuctions
     read complete
       nbndx  =    10  nbnd   =    10  natomwfc =    64  npwx   =    9600
     nelec  =  20.00  nkb   =    52  ngl    =    4494
     WRITING PATTERNS TO FILE drho.pat
       phonons of SnO at Gamma                                                    
                    ........................
                    .........................
                    ........................
       Dielectric constant from finite-differences
            (       9.668658880       0.000000000       0.000000000 )
          (       0.000000000       9.668658880       0.000000000 )
          (       0.000000000       0.000000000       6.794783712 )
                Electro-optic tensor is defined as 
            the derivative of the dielectric tensor 
              with respect to one electric field 
                 units are Rydberg a.u. 
              to obtain the static chi^2 multiply by 1/2  
              to convert to pm/Volt multiply per 2.7502  
  
          Electro-optic tensor in cartesian axis: 
            (       0.000000000       0.000000000       0.000000000 )
          (       0.000000000       0.000000000       0.000000000 )
          (       0.000000000       0.000000000       0.000000000 )
            (       0.000000000       0.000000000       0.000000000 )
          (       0.000000000       0.000000000       0.000000000 )
          (       0.000000000       0.000000000       0.000000000 )
            (       0.000000000       0.000000000       0.000000000 )
          (       0.000000000       0.000000000       0.000000000 )
          (       0.000000000       0.000000000       0.000000000 )
  
     Computing Second order response 
  
      iter #   1   av.it.:  13.9
      thresh= 0.100E-01 alpha_mix =  0.700 |ddv_scf|^2 =  0.476E-02 "
   
  It stopped here without any error warning.
  So I the change parameters such as tr2_ph, kpoints and ecut to the lower limitition. It run correctly. But  "Electro-optic tensor in cartesian axis" is the same as above. So please help me with this.
   
ps: the  phonon frequencies at Gama point  can be calculated freely.

		
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