[Wien] vol opt problem of spin-pol hematite

[swati chaudhury]

Dear Wien users,
                  I want to do volume optimization calculation of  of spin-polarized hematite. But volume is not optimized even at ‘-12%’. By using optimum inputs as I used in non-magnetic hematite calculation c/a of spin-pol case is completed smoothly at ‘1.5%’ but failed in vol-opt case. Is there any problem in my inputs or way of calculation? Please suggest to rectify the calculation.
  I have used following inputs:
  Cell-parameters:
  a = b = 5.035 ang, c = 13.72 ang
  Space group: 167 R-3c
  Rmt (Fe) = 1.70, Rmt (O) = 1.70
  Cut-off = -9.0
  RmtKmax = 7.65, Emin = -9.0, Emax = 2.5
  Mixing factor = 0.40
  Gmax =14.0, 13 GGA is chosen.
  K-points = 1400
  I have used wien_07.3 version.
   
  In addition, I have noticed strange observations that calculated binding energy is highly negative than experimental value using optimized inputs (e.g k-points, RmtKmax etc.) in some cases. Why is it so?  
  Thanks in advance.
  Regards.
  swati
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://zeus.theochem.tuwien.ac.at/pipermail/wien/attachments/20080318/8cd1ac49/attachment.html