<div dir="ltr">Hi all,<div><br></div><div>I am trying to do cell optimization of a goethite FeOOH unit cell.  The lattice parameters of the considered unit cell are a=9.91340  b=3.0128, c=4.58 ( the same values I used in cp2k).</div><div><br></div><div>I have tested all three cases (direct cell opt, geo opt, MD) of the CELL_OPT and </div><div><br></div><div>The cell optimized values are approximately a=9.33, b=3.063 c=4.179. </div><div><b>The experiment values of lattice constants are a=9.96 b=3.02  c=4.62. </b><br></div><div><b><br></b></div><div><b>I want to obtain the optimized values close to expt. values. </b></div><div><b><br></b></div><div>In trail and error, I have used STESS_TENSOR NUMERICAL, I have disabled D3 correction and I have also used zero pressure.  </div><div><br></div><div><br></div><div><br></div><div>Below is my input file. </div><div><div>&Global                                                                                                                                                                                                        </div><div>  PROJECT goethite_cellopt                                                                                                                                                                                     </div><div>  RUN_TYPE CELL_OPT                                                                                                                                                                                            </div><div>  PRINT_LEVEL LOW                                                                                                                                                                                              </div><div>&END GLOBAL                                                                                                                                                                                                    </div><div>                                                                                                                                                                                                               </div><div>&FORCE_EVAL                                                                                                                                                                                                    </div><div>  METHOD Quickstep                                                                                                                                                                                             </div><div>  STRESS_TENSOR ANALYTICAL                                                                                                                                                                                     </div><div>  &DFT                                                                                                                                                                                                         </div><div>    BASIS_SET_FILE_NAME BASIS_MOLOPT                                                                                                                                                                           </div><div>    POTENTIAL_FILE_NAME GTH_POTENTIALS                                                                                                                                                                         </div><div>    CHARGE 0                                                                                                                                                                                                   </div><div>    MULTIPLICITY 1                                                                                                                                                                                             </div><div>    &MGRID                                                                                                                                                                                                     </div><div>      NGRIDS 5                                                                                                                                                                                                 </div><div>      CUTOFF 600                                                                                                                                                                                               </div><div>      REL_CUTOFF 60                                                                                                                                                                                            </div><div>    &END                                                                                                                                                                                                       </div><div>    &QS                                                                                                                                                                                                        </div><div>       METHOD GPW                                                                                                                                                                                              </div><div>       EPS_DEFAULT 1.0E-12                                                                                                                                                                                     </div><div>       EXTRAPOLATION ASPC                                                                                                                                                                                      </div><div>       EXTRAPOLATION_ORDER 4                                                                                                                                                                                   </div><div>    &END                                                                                                                                                                                                       </div><div>    &SCF                                                                                                                                                                                                       </div><div>      SCF_GUESS ATOMIC                                                                                                                                                                                         </div><div>      MAX_SCF 1500                                                                                                                                                                                                                                               </div></div><div><div>      EPS_SCF 1.0E-8                                                                                                                                                                                           </div><div>      &OUTER_SCF                                                                                                                                                                                               </div><div>        MAX_SCF 30                                                                                                                                                                                             </div><div>        EPS_SCF 1.0E-8                                                                                                                                                                                         </div><div>      &END                                                                                                                                                                                                     </div><div>      ADDED_MOS  30                                                                                                                                                                                            </div><div>      CHOLESKY INVERSE                                                                                                                                                                                         </div><div>      &SMEAR  ON                                                                                                                                                                                               </div><div>        METHOD FERMI_DIRAC                                                                                                                                                                                     </div><div>        ELECTRONIC_TEMPERATURE [K] 300                                                                                                                                                                         </div><div>      &END SMEAR                                                                                                                                                                                               </div><div>      &DIAGONALIZATION                                                                                                                                                                                         </div><div>        ALGORITHM STANDARD                                                                                                                                                                                     </div><div>      &END DIAGONALIZATION                                                                                                                                                                                     </div><div>      &MIXING                                                                                                                                                                                                  </div><div>        METHOD  BROYDEN_MIXING                                                                                                                                                                                 </div><div>        ALPHA   0.1                                                                                                                                                                                            </div><div>        BETA    1.5                                                                                                                                                                                            </div><div>        NBROYDEN 8                                                                                                                                                                                             </div><div>      &END MIXING                                                                                                                                                                                              </div><div>    &END SCF                                                                                                                                                                                                   </div><div>    &XC                                                                                                                                                                                                        </div><div>      &XC_FUNCTIONAL PBE                                                                                                                                                                                       </div><div>      &END XC_FUNCTIONAL                                                                                                                                                                                       </div><div>      &VDW_POTENTIAL                                                                                                                                                                                           </div><div>        POTENTIAL_TYPE PAIR_POTENTIAL                                                                                                                                                                              </div><div>        &PAIR_POTENTIAL                                                                                                                                                                                        </div><div>          PARAMETER_FILE_NAME dftd3.dat                                                                                                                                                                        </div><div>          TYPE DFTD3                                                                                                                                                                                           </div><div>          REFERENCE_FUNCTIONAL PBE                                                                                                                                                                             </div><div>          R_CUTOFF [angstrom] 15                                                                                                                                                                               </div><div>        &END                                                                                                                                                                                                   </div><div>      &END VDW_POTENTIAL                                                                                                                                                                                       </div><div>    &END XC                                                                                                                                                                                                    </div><div>  &END DFT                                                                                                                                                                                                     </div><div>                                                                                                                                                                                                               </div><div>  &SUBSYS                                                                                                                                                                                                      </div><div>    &CELL                                                                                                                                                                                                      </div><div>      ABC [angstrom] 9.91340 3.01280 4.58000                                                                                                                                                                   </div><div>      PERIODIC XYZ                                                                                                                                                                                             </div><div>    &END CELL                                                                                                                                                                                                  </div><div>    &TOPOLOGY                                                                                                                                                                                                  </div><div>      COORD_FILE_NAME <a href="http://goethite_unitcell.xyz" target="_blank">goethite_unitcell.xyz</a>                                                                                                                                                                    </div><div>      COORD_FILE_FORMAT XYZ                                                                                                                                                                                    </div><div>      &CENTER_COORDINATES T                                                                                                                                                                                    </div><div>      &END CENTER_COORDINATES                                                                                                                                                                                  </div><div>    &END                                                                                                                                                                                                       </div><div>    &KIND H                                                                                                                                                                                                    </div><div>      BASIS_SET DZVP-MOLOPT-SR-GTH                                                                                                                                                                             </div><div>      POTENTIAL GTH-PBE-q1                                                                                                                                                                                     </div><div>    &END KIND                                                                                                                                                                                                                                                                                                                                                            &KIND Fe                                                                                                                                                                                                   </div><div>      BASIS_SET DZVP-MOLOPT-SR-GTH                                                                                                                                                                             </div><div>      POTENTIAL GTH-PBE-q16                                                                                                                                                                                    </div><div>    &END KIND                                                                                                                                                                                                  </div><div>    &KIND O                                                                                                                                                                                                    </div><div>      BASIS_SET DZVP-MOLOPT-SR-GTH                                                                                                                                                                             </div><div>      POTENTIAL GTH-PBE-q6                                                                                                                                                                                     </div><div>    &END KIND                                                                                                                                                                                                  </div><div>                                                                                                                                                           <br></div><div>  &END SUBSYS                                                                                                                                                                                                  </div><div>&END FORCE_EVAL                                                                                                                                                                                                </div><div>                                                                                                                                                                                                               </div><div>&MOTION                                                                                                                                                                                                        </div><div> &CELL_OPT                                                                                                                                                                                                     </div><div>   OPTIMIZER BFGS                                                                                                                                                                                              </div><div>   MAX_ITER  5000                                                                                                                                                                                           </div><div>   KEEP_ANGLES T </div><div>   EXTERNAL_PRESSURE 1.01325 0 0 0 1.01325 0 0 0 1.01325                                                                                                                                                                                  </div><div> &END                                                                                                                                                                                                          </div><div>&END  </div><div><br></div><div><br></div><div>Goethite unit cell</div><div><br></div><div>16                                                                                                                                                                                                             <br></div><div>Fe H O2                                                                                                                                                                                                        </div><div>Fe    1.446365    0.753200    4.357412                                                                                                                                                                         </div><div>Fe    8.467034    2.259600    0.222588                                                                                                                                                                         </div><div>Fe    3.510335    2.259600    2.067412                                                                                                                                                                         </div><div>Fe    6.403065    0.753200    2.512588                                                                                                                                                                         </div><div> H    8.912147    0.753200    2.752580                                                                                                                                                                         </div><div> H    1.001253    2.259600    1.827420                                                                                                                                                                         </div><div> H    5.957953    2.259600    0.462580                                                                                                                                                                         </div><div> H    3.955446    0.753200    4.117420                                                                                                                                                                         </div><div> O    7.940633    0.753200    1.305300                                                                                                                                                                         </div><div> O    1.972767    2.259600    3.274700                                                                                                                                                                         </div><div> O    6.929466    2.259600    3.595300                                                                                                                                                                         </div><div> O    2.983933    0.753200    0.984700                                                                                                                                                                         </div><div> O    9.400877    0.753200    3.682320                                                                                                                                                                         </div><div> O    0.512523    2.259600    0.897680                                                                                                                                                                         </div><div> O    5.469223    2.259600    1.392320                                                                                                                                                                         </div><div> O    4.444177    0.753200    3.187680        </div><div><br></div><div><br></div><div>Please let me know if you have any suggestions. </div><div>                                          </div><div>                  </div></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div></div>