[Pw_forum] vc-relax

Detlef Schmicker d.schmicker at yahoo.de
Mon Feb 19 09:40:51 CET 2007


Thanks a lot for the response Paolo,

I changed
> >                      ecutwfc = 50 ,
> >                      ecutrho = 300 ,

but the behaviour does not seem better. 

I calculated for 76 hours now: The total energy is
going down as expected:

!    total energy              = -1961.72747371 Ry
!    total energy              = -1961.72856632 Ry
!    total energy              = -1961.73085136 Ry
!    total energy              = -1961.73414783 Ry
!    total energy              = -1961.73790040 Ry
!    total energy              = -1961.74093832 Ry
!    total energy              = -1961.74316902 Ry
!    total energy              = -1961.74619617 Ry
!    total energy              = -1961.74717438 Ry
!    total energy              = -1961.74824660 Ry
!    total energy              = -1961.75286729 Ry
!    total energy              = -1961.75525825 Ry
!    total energy              = -1961.75771758 Ry
!    total energy              = -1961.76046869 Ry
!    total energy              = -1961.76271513 Ry
!    total energy              = -1961.76306347 Ry
!    total energy              = -1961.76500771 Ry


But the total force is not behaving as I expect it:
     Total force =     0.023362     Total SCF
correction =     0.005194
     Total force =     0.020491     Total SCF
correction =     0.003656
     Total force =     0.022102     Total SCF
correction =     0.005813
     Total force =     0.020633     Total SCF
correction =     0.004226
     Total force =     0.020646     Total SCF
correction =     0.006542
     Total force =     0.031831     Total SCF
correction =     0.007696
     Total force =     0.047256     Total SCF
correction =     0.009570
     Total force =     0.044493     Total SCF
correction =     0.007352
     Total force =     0.079400     Total SCF
correction =     0.016914
     Total force =     0.080773     Total SCF
correction =     0.014257
     Total force =     0.044399     Total SCF
correction =     0.006424
     Total force =     0.048366     Total SCF
correction =     0.004975
     Total force =     0.046974     Total SCF
correction =     0.009519
     Total force =     0.041070     Total SCF
correction =     0.009807
     Total force =     0.049513     Total SCF
correction =     0.004709
     Total force =     0.089950     Total SCF
correction =     0.010658
     Total force =     0.074462     Total SCF
correction =     0.011620

and the stress:
          total   stress  (Ry/bohr**3)                
  (kbar)     P=  -20.71
          total   stress  (Ry/bohr**3)                
  (kbar)     P=  -20.18
          total   stress  (Ry/bohr**3)                
  (kbar)     P=  -19.34
          total   stress  (Ry/bohr**3)                
  (kbar)     P=  -17.83
          total   stress  (Ry/bohr**3)                
  (kbar)     P=  -11.93
          total   stress  (Ry/bohr**3)                
  (kbar)     P=   -6.68
          total   stress  (Ry/bohr**3)                
  (kbar)     P=   -0.79
          total   stress  (Ry/bohr**3)                
  (kbar)     P=   -7.57
          total   stress  (Ry/bohr**3)                
  (kbar)     P=   -8.15
          total   stress  (Ry/bohr**3)                
  (kbar)     P=   -5.28
          total   stress  (Ry/bohr**3)                
  (kbar)     P=   -6.21
          total   stress  (Ry/bohr**3)                
  (kbar)     P=   -2.72
          total   stress  (Ry/bohr**3)                
  (kbar)     P=   -4.19
          total   stress  (Ry/bohr**3)                
  (kbar)     P=    0.91
          total   stress  (Ry/bohr**3)                
  (kbar)     P=    1.61
          total   stress  (Ry/bohr**3)                
  (kbar)     P=    3.21
          total   stress  (Ry/bohr**3)                
  (kbar)     P=   -6.89


and for completness I send the temperatures:
     Ekin =     0.00000000 Ry    T =    0.0 K  Etot =
-1961.72747371
     Ekin =     0.00111722 Ry    T =    3.8 K  Etot =
-1961.72744910
     Ekin =     0.00347429 Ry    T =    7.8 K  Etot =
-1961.72737707
     Ekin =     0.00703939 Ry    T =   13.2 K  Etot =
-1961.72710844
     Ekin =     0.01110756 Ry    T =   19.3 K  Etot =
-1961.72679284
     Ekin =     0.01345837 Ry    T =   24.6 K  Etot =
-1961.72747996
     Ekin =     0.01531120 Ry    T =   29.1 K  Etot =
-1961.72785782
     Ekin =     0.01380786 Ry    T =   31.7 K  Etot =
-1961.73238831
     Ekin =     0.01215649 Ry    T =   32.9 K  Etot =
-1961.73501789
     Ekin =     0.01207252 Ry    T =   33.8 K  Etot =
-1961.73617409
     Ekin =     0.01067002 Ry    T =   34.0 K  Etot =
-1961.74219728
     Ekin =     0.00889187 Ry    T =   33.7 K  Etot =
-1961.74636637
     Ekin =     0.01081347 Ry    T =   33.9 K  Etot =
-1961.74690411
     Ekin =     0.01202862 Ry    T =   34.5 K  Etot =
-1961.74844007
     Ekin =     0.01322190 Ry    T =   35.2 K  Etot =
-1961.74949323
     Ekin =     0.01505569 Ry    T =   36.3 K  Etot =
-1961.74800778
     Ekin =     0.01128462 Ry    T =   36.4 K  Etot =
-1961.75372309


I tried several values for dt (50 -- 300) and did the
calculation with lower 
ecutwfc = 30 , ecutrho = 120 ,
in the last weeks. I also calculated 5 times longer
than the actual 78 hours, but nothing changed the
behaviour, that the total force is not going down
below approx. 0.02

Perhaps somebody can help.

Thanks a lot, Detlef

P.S.: I have strong evidence for unusual mail problem
with the list :-)

--- Paolo Giannozzi <giannozz at nest.sns.it> schrieb:

> 
> On Feb 15, 2007, at 18:23 , Detlef Schmicker wrote:
> 
> > (In case an list administrator reads this, I can
> send the
> > error messages to him).
> 
> unless you have solid evidence that it is not the
> usual
> problem (i.e. e-mail mismatch), please don't waste
> your
> time and mine
> 
> >                      ecutwfc = 50 ,
> >                      ecutrho = 190 ,
> 
> not good: for USPP, ecutrho should be larger than
> 4*ecutwfc
> 
> Paolo
> ---
> Paolo Giannozzi, Democritos and University of Udine,
> Italy
> 
> 
> _______________________________________________
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum
> 





	
		
___________________________________________________________ 
Der frühe Vogel fängt den Wurm. Hier gelangen Sie zum neuen Yahoo! Mail: http://mail.yahoo.de



More information about the users mailing list