Geometry optimization of SiO2

[Shun]

Hi

I am a beginner of cp2k and trying to optimize the structure of SiO2 to 
make sure that cp2k works for zeolite I want to calculate.
The following input file was submitted and the BFGS Optimization was fine 
first. But, the SCF of the 3rd optimization cycle was not converged and I 
saw the structure made big change.
What is the problem of this? I attempted also other structures of SiO2 but 
same problem happened again.
If you have a advice, suggestion or solution, let me know please.

 
**************************
&GLOBAL
   PROJECT_NAME sio2
   RUN_TYPE  GEO_OPT
 &END GLOBAL
 &MOTION
   &GEO_OPT
     OPTIMIZER BFGS
     MAX_ITER  5000
     MAX_DR     1.0000000000000000E-4
     MAX_FORCE     1E-6
   &END GEO_OPT
 &END MOTION
 &FORCE_EVAL
   METHOD  QS
   &DFT
     BASIS_SET_FILE_~/cp2k-3.0/data/GTH_BASIS_SETS
     POTENTIAL_FILE_NAME ~/cp2k-3.0/data/POTENTIAL
    &SCF
       EPS_SCF 1.0E-6
       MAX_SCF 200
       &MIXING T
          ALPHA 0.1
       &END MIXING
     &END SCF
     &QS
       METHOD  GPW
     &END QS
     &MGRID
       CUTOFF    300
     &END MGRID
     &XC
       &XC_FUNCTIONAL
       &END XC_FUNCTIONAL
     &END XC
   &END DFT
   &SUBSYS

&CELL
  PERIODIC XYZ
  A   4.916000000000000   0.000000000000000   0.000000000000000
  B  -2.458000000000000   4.257380885004300   0.000000000000000
  C   0.000000000000000   0.000000000000000   5.407000000000000
&END CELL

&COORD
Si -1.529859200000000   3.118957236354151   4.758700699999999
Si -0.080622400000000   1.117988220402129   1.154394500000000
Si  2.379098200000000   0.860416676859369   2.956006900000000
O  0.000000000000000   0.000000000000000   0.000000000000000
O -0.594098600000000   2.495250936701020   0.517990600000000
O -0.600489400000000   3.740960583653279   3.594573599999999
O  1.372301400000000   1.357678764227871   1.798908900000000
O  2.451363400000000   1.978404897261498   4.123918900000000
O  3.828826600000000   0.623706299653130   2.314736700000000
&END COORD

     &KIND Si
       BASIS_SET DZVP-GTH
       POTENTIAL GTH-PBE-q4
     &END KIND
     &KIND O
       BASIS_SET DZVP-GTH
       POTENTIAL GTH-PBE-q6
     &END KIND
   &END SUBSYS
 &END FORCE_EVAL

*********************************************
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20170206/90af2d5c/attachment.htm>