[Pw_forum] atomic position with crystal_sg

[Uttam Paliwal]

hi

I am running the Si example given in PWgui-6.1. When I give space group 227
and atomic position 0 0 0 then Xcrysden is showing Simple FCC structure of
Si while withoutspace group number the original file is showing diamond
structure in xcrysden. Also the calculated energy is different. I am giving
here the input file for crystal_sg. Kindly suggest the corrections to
reproduce the results
i
Silicon
 &CONTROL
                 calculation = 'scf' ,
                restart_mode = 'from_scratch' ,
                      outdir =
'/cygdrive/d/ESPRESSO-6.1/qe-6.1/PWgui-6.1/TMP/' ,
                  pseudo_dir = '/cygdrive/d/AA_QE_Si/pseudo Si/' ,
                      prefix = 'silicon' ,
                     tstress = .true. ,
                     tprnfor = .true. ,
 /
 &SYSTEM
                       ibrav = 2,
                   celldm(1) = 10.20,
                         nat = 1,
                        ntyp = 1,
                     ecutwfc = 18.0 ,
                     ecutrho = 72.0 ,
                 space_group = 227 ,
               origin_choice = 2 ,
 /
 &ELECTRONS
                    conv_thr = 1.0d-8 ,
                 mixing_mode = 'plain' ,
                 mixing_beta = 0.7 ,
 /
ATOMIC_SPECIES
   Si   28.08600  Si.pbe-rrkj.UPF
ATOMIC_POSITIONS crystal_sg
   Si      0.000000000    0.000000000    0.000000000    0  0  0
K_POINTS
10
   0.125000000    0.125000000    0.125000000      1.000000000
   0.125000000    0.125000000    0.375000000      3.000000000
   0.125000000    0.125000000    0.625000000      3.000000000
   0.125000000    0.125000000    0.875000000      3.000000000
   0.125000000    0.375000000    0.375000000      3.000000000
   0.125000000    0.375000000    0.625000000      6.000000000
   0.125000000    0.375000000    0.875000000      6.000000000
   0.125000000    0.625000000    0.625000000      3.000000000
   0.375000000    0.375000000    0.375000000      1.000000000
   0.375000000    0.375000000    0.625000000      3.000000000
-- 


thanks and regards
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20170422/7b84a65e/attachment.html>