<div dir="ltr"><div><font face="times new roman, serif">Hi, everyone in cp2k community, </font></div><font face="times new roman, serif">As the title suggested, I have been calculating band gap of bilayer graphene under external bias using cp2k 4.1. </font><div><font face="times new roman, serif">But the band gap reported in literature can reach 170~190 meV if external bias reach 2 V/nm (i.e. 0.2V/angstrom in my setting). </font></div><div><font face="times new roman, serif">In my calculation, the band gap can only reach 110~115meV. </font></div><div><font face="times new roman, serif">Can anyone give some suggestion ? Here is my input file.</font></div><div><font face="times new roman, serif"><br></font></div><div><font face="times new roman, serif"><div class="prettyprint" style="background-color: rgb(250, 250, 250); border: 1px solid rgb(187, 187, 187); word-wrap: break-word;"><code class="prettyprint"><div class="subprettyprint"><div class="subprettyprint">@SET PROJ_NAME bilayerBias_02</div><div class="subprettyprint">@SET BS_NAME biBias_02.bs</div><div class="subprettyprint">@SET IF_USE_EXPOT YES</div><div class="subprettyprint">@SET ELEC_MAGNI 0.2</div><div class="subprettyprint"><br></div><div class="subprettyprint">&GLOBAL</div><div class="subprettyprint">  PROJECT ${PROJ_NAME}</div><div class="subprettyprint">  RUN_TYPE ENERGY</div><div class="subprettyprint">  PRINT_LEVEL MEDIUM</div><div class="subprettyprint">&END GLOBAL</div><div class="subprettyprint"><br></div><div class="subprettyprint">&FORCE_EVAL</div><div class="subprettyprint">  METHOD Quickstep</div><div class="subprettyprint">  &DFT</div><div class="subprettyprint">    BASIS_SET_FILE_NAME BASIS_MOLOPT</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre"> </span>POTENTIAL_FILE_NAME POTENTIAL</div><div class="subprettyprint"><br></div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">     </span>&MGRID</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">  </span>  NGRIDS 5</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre"> </span>  CUTOFF 350</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">       </span>  REL_CUTOFF 60</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">    </span>&END MGRID</div><div class="subprettyprint"><br></div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">    </span>&POISSON</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">        </span>  PERIODIC XYZ</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">     </span>&END POISSON</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">    </span>&QS</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">     </span>  EXTRAPOLATION USE_GUESS</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">  </span>&END QS</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre"> </span>&SCF</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">    </span>  SCF_GUESS ATOMIC</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre"> </span>  EPS_SCF 1.0E-6</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">   </span>  MAX_SCF 300</div><div class="subprettyprint"><br></div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">    </span>  ADDED_MOS 2</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">      </span>  &SMEAR ON</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">    </span>    METHOD FERMI_DIRAC</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">            </span>ELECTRONIC_TEMPERATURE [K] 300</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">      </span>  &END SMEAR</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">   </span>  &DIAGONALIZATION</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">     </span>    ALGORITHM STANDARD</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">            </span>EPS_ADAPT 0.01</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">      </span>  &END DIAGONALIZATION</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre"> </span>  &MIXING</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">      </span>    METHOD BROYDEN_MIXING</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">         </span>ALPHA 0.2</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">           </span>BETA 1.5</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">            </span>NBROYDEN 8</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">  </span>  &END MIXING</div><div class="subprettyprint">    &END SCF</div><div class="subprettyprint">@IF ( ${IF_USE_EXPOT} == YES )</div><div class="subprettyprint">    &EXTERNAL_POTENTIAL</div><div class="subprettyprint">        FUNCTION (A/B) * Z</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">               </span>VALUES [eV] 0.2  [angstrom] 1.0</div><div class="subprettyprint">    <span class="Apple-tab-span" style="white-space:pre">      </span>PARAMETERS A B</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">      </span>&END</div><div class="subprettyprint">@ENDIF</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">      </span>&XC</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">     </span>  &XC_FUNCTIONAL PBE</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">   </span>  &END XC_FUNCTIONAL</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">   </span>  &XC_GRID</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">             </span>XC_SMOOTH_RHO NN50</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">          </span>XC_DERIV NN50_SMOOTH</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">        </span>  &END XC_GRID</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre"> </span>  &VDW_POTENTIAL</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">               </span>POTENTIAL_TYPE PAIR_POTENTIAL</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">               </span>  &PAIR_POTENTIAL</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">                      </span>PARAMETER_FILE_NAME dftd3.dat</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">                       </span>TYPE DFTD3</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">                  </span>REFERENCE_FUNCTIONAL PBE</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">                    </span>R_CUTOFF [angstrom] 16</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">              </span>  &END</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre"> </span>  &END VDW_POTENTIAL</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">   </span>&END XC</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre"> </span>&KPOINTS</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">        </span>  SCHEME MONKHORST-PACK 11 11 1</div><div class="subprettyprint">      SYMMETRY OFF</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">       </span>  WAVEFUNCTIONS REAL</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">       </span>  FULL_GRID .TRUE.</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre"> </span>  PARALLEL_GROUP_SIZE 0</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">    </span>  &BAND_STRUCTURE</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">              </span>ADDED_MOS 4</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">         </span>FILE_NAME ${BS_NAME}</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">                </span>&KPOINT_SET</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">             </span>  UNITS CART_BOHR</div><div class="subprettyprint">          SPECIAL_POINT 0.0 0.0 0.0</div><div class="subprettyprint">          SPECIAL_POINT 1./2. 0.0 0.0</div><div class="subprettyprint">          SPECIAL_POINT 2./3. 1./3. 0.0</div><div class="subprettyprint">          SPECIAL_POINT 0.0 0.0 0.</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">             </span>  NPOINTS 160</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">              </span>&END</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">    </span>  &END BAND_STRUCTURE</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">  </span>&END KPOINTS</div><div class="subprettyprint">  &END DFT</div><div class="subprettyprint">  &SUBSYS</div><div class="subprettyprint">    &CELL</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">        </span>  ABC [angstrom] 2.4612 2.4612 16.75</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">       </span>  ALPHA_BETA_GAMMA 90. 90. 60.</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">     </span>  SYMMETRY HEXAGONAL</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">       </span>  PERIODIC XYZ</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">     </span>  MULTIPLE_UNIT_CELL 1 1 1</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre"> </span>&END CELL</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">       </span>&TOPOLOGY</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">       </span>  MULTIPLE_UNIT_CELL 1 1 1</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre"> </span>&END TOPOLOGY</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">   </span>&COORD</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">  </span>  SCALED</div><div class="subprettyprint">      C 0.    0.    4./5.</div><div class="subprettyprint">      C 1./3. 1./3. 4./5.</div><div class="subprettyprint">      C 2./3. 2./3. 5./5.</div><div class="subprettyprint">      C 3./3. 3./3. 5./5.</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">       </span>&END</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">    </span>&KIND C</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre"> </span>  ELEMENT C</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">        </span>  BASIS_SET TZVP-MOLOPT-GTH</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">        </span>  POTENTIAL GTH-BLYP-q4</div><div class="subprettyprint"><span class="Apple-tab-span" style="white-space:pre">    </span>&END KIND</div><div class="subprettyprint">  &END SUBSYS</div><div class="subprettyprint"><br></div><div class="subprettyprint">&END FORCE_EVAL</div></div></code></div><br><br></font></div><div><font face="times new roman, serif"><br></font></div></div>