[Pw_forum] pseudopotential

[wumindt2]

Dear All,

I met some problem when printing the stress using different pseudopotentials. The structure i calculated
is CO2 solid structure.
Using the same structure, when the pseudopotentials are C.pbe-rrkjus.UPF and O.pbe-rrkjus.UPF,
the stress tensor i got is 

     entering subroutine stress ...
                                
          total   stress  (Ry/bohr**3)                   (kbar)     P=  175.92
   0.00114704   0.00000000   0.00000000        168.74      0.00      0.00
   0.00000000   0.00121085   0.00000007          0.00    178.12      0.01
   0.00000000   0.00000007   0.00122973          0.00      0.01    180.90

However, when i changed the pseudopotential to C.pbe-mt_gipaw.UPF and O.pbe-van_gipaw.UPF , the stress tensot
i got  is

     entering subroutine stress ...
                                
          total   stress  (Ry/bohr**3)                   (kbar)     P=  252.11
   0.00113269   0.00000000   0.00000000        166.62      0.00      0.00
   0.00000000   0.00225526   0.00000002          0.00    331.76      0.00
   0.00000000   0.00000002   0.00175342          0.00      0.00    257.94


Why we will get so much different stress using the different pseudopotential ? The structures i ued are exact same.

Thanks for any help.

With kind regards,

Min Wu
2010-11-5
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://www.democritos.it/pipermail/pw_forum/attachments/20101106/907af28f/attachment.htm