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[scabuk@cu.edu.tr]

Dear abinit users,

Nowdays, I would like to calculated some structure parameters the 
orthorhombic phase Amm2 (38) of KNbO3. The lattice constans (a,b,c) and 
atomic position are the experimental data (ref. A.W. Hrwat, J. Phy. C:solid 
state Phys. vol.6,pp.2559,1973).  I try alot of probobility, e.g. I change 
the order of lattice constans from (a,b,c) to (c,a,b) and also xred, 
yred,zred and changed atomic position, etc. But I couldn't get the space 
group Amm2. I can use LDA pseudotantials. Output file was given me the space 
group Pmm2 (25).  How can I get the space group Amm2 ? Please help!

Thanks in advance.

Best Regards.
e-mail:scabuk@cu.edu.tr

my input file:
#Definition of the k-point grids
kptopt 1          
nshiftk 1
shiftk  0.5 0.5 0.5  

ngkpt  4 4 4 
getwfk -1         

#Definition of the unit cell

acell 7.5041 10.7601 10.8092   
#rprim  1.0  1.0 0.0
       -1.0 1.0 0.0
       0.0  0.0 1.0
        
         
angdeg 90 90 90           
          
#Definition of the atom types
ntypat 3          
znucl 19 41 8                           

#Definition of the atoms
 natom 10          
 typat 2*1 2*2 6*3       
 xred              
   0.0    0.0  0.0138
   0.0    0.5  0.5138
   0.5    0.0  0.5
   0.5    0.5  0.0
   0.0    0.0  0.4636 
   0.0    0.5  0.0364 
   0.5   0.7524 0.7158   
   0.5   0.2476 0.7158 
   0.5   0.2524 0.2158  
   0.5   0.7476 0.2158   
    
   
#Definition of the planewave basis set
ecut  35.0         

#Definition of the SCF procedure
nstep 1000         
toldfe 1.0d-6    

output file:
Symmetries : space group Pm m 2 (# 25); Bravais oP (primitive ortho.)
================================================================================
 Values of the parameters that define the memory need of the present run
   intxc =         0  ionmov =         0    iscf =         5     ixc =        
 7
  lmnmax =         4   lnmax =         4   mband =        26  mffmem =        
 1
P  mgfft =        60   mkmem =         8 mpssoang=         4     mpw =      
8647
  mqgrid =      1201   natom =        10    nfft =    144000    nkpt =        
 8
  nloalg =         4  nspden =         1 nspinor =         1  nsppol =        
 1
    nsym =         4  n1xccc =      2501  ntypat =         3  occopt =        
 1
================================================================================