[Pw_forum] Reply: ground state structure calculation -reg.,

[Suresh A]

Dear Everybody,
                        Thank You for your reply.
Dear Sava,
                In your reply you have quoted that " you need not worry
about symmetry conservation" is that means did i use any symmetry
conservation like card in my input file?


Dear Giuseppe,
                      First i did vc-relax with ecutwfc=50 and ecutrho=200.
for that input file that input file iget output as follows.
        entering subroutine stress ...

          total   stress  (Ry/bohr**3)                   (kbar)     P=
-0.08
  -0.00000057  -0.00000025   0.00000000         -0.08     -0.04      0.00
  -0.00000025  -0.00000057   0.00000000         -0.04     -0.08      0.00
   0.00000000   0.00000000  -0.00000047          0.00      0.00     -0.07


     bfgs converged in   7 scf cycles and   5 bfgs steps
     (criteria: energy < 0.10E-04, force < 0.10E-03, cell < 0.20E+01)

     End of BFGS Geometry Optimization

     Final enthalpy =    -142.8393726978 Ry
Begin final coordinates
     new unit-cell volume =    365.14428 a.u.^3 (    54.10880 Ang^3 )

CELL_PARAMETERS (alat=  8.68089163)
   0.951086548   0.000003754   0.000000000
   0.000003754   0.951086548   0.000000000
   0.000000000   0.000000000   0.617065718


         entering subroutine stress ...

          total   stress  (Ry/bohr**3)                   (kbar)     P=
-233.71
  -0.00161914  -0.00000028   0.00000000       -238.18     -0.04      0.00
  -0.00000028  -0.00161914   0.00000000         -0.04   -238.18      0.00
   0.00000000   0.00000000  -0.00152791          0.00      0.00   -224.76


     Writing output data file pwscf.save

there was a very large difference between last converged structures kbar
values so i suddenly change energy cuttoffs values to 200/800. Futhermore i
create this inputfile with the help of pwgui. Pwgui automatically inserted
exxdiv_treatment card which i didn't notice in my calculation. I got some
clues on my calculation. I will reply soon to your answer.

Dear Emine,
                 I took pseudopotential as it is from quantum espresso
website. i didn't check on it whether it is hard pseudopotential or soft
one. the i choose higher cutoff because to reduce kbar difference as i
shown above.
After i check my calculation i will reply to you.
                         Thank you  all once again
                  With Regards,
A.Suresh,
Project Fellow,
Madurai Kamaraj University,
Madurai.
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