<div dir="ltr">Hi! I am a beginner in CP2K and I encountered with such problem: when I carried out the test CUTOFF value optimization in single point mode the total energy has significant changes even at large CUTOFF values (350-500 Ry). The REL_CUTOFF value is constant (60 Ry). For test example I chose the small maleimide molecule. I tried to enlarge the cell volume (ABC = 30, 30, 30), but for larger cell I obtained the same picture for TOTAL_E changes. What am I doing wrong? I will be very grateful for your advices. My ultimate goal is to study the mechanisms of organic reactions in a solvent medium by DFT molecular dynamics.<div><div class="prettyprint" style="background-color: rgb(250, 250, 250); border-color: rgb(187, 187, 187); border-style: solid; border-width: 1px; word-wrap: break-word;"><code class="prettyprint"><div class="subprettyprint"><span style="color: #000;" class="styled-by-prettify">CUTOFF </span><span style="color: #660;" class="styled-by-prettify">(</span><span style="color: #606;" class="styled-by-prettify">Ry</span><span style="color: #660;" class="styled-by-prettify">)</span><span style="color: #000;" class="styled-by-prettify"> TOTAL_E<br></span><span style="color: #066;" class="styled-by-prettify">50</span><span style="color: #000;" class="styled-by-prettify"> </span><span style="color: #660;" class="styled-by-prettify">-</span><span style="color: #066;" class="styled-by-prettify">64.842624462853280</span><span style="color: #000;" class="styled-by-prettify"><br></span><span style="color: #066;" class="styled-by-prettify">150</span><span style="color: #000;" class="styled-by-prettify"> </span><span style="color: #660;" class="styled-by-prettify">-</span><span style="color: #066;" class="styled-by-prettify">66.596463098602229</span><span style="color: #000;" class="styled-by-prettify"><br></span><span style="color: #066;" class="styled-by-prettify">200</span><span style="color: #000;" class="styled-by-prettify"> </span><span style="color: #660;" class="styled-by-prettify">-</span><span style="color: #066;" class="styled-by-prettify">66.596086697673911</span><span style="color: #000;" class="styled-by-prettify"><br></span><span style="color: #066;" class="styled-by-prettify">250</span><span style="color: #000;" class="styled-by-prettify"> </span><span style="color: #660;" class="styled-by-prettify">-</span><span style="color: #066;" class="styled-by-prettify">66.593017494126642</span><span style="color: #000;" class="styled-by-prettify"><br></span><span style="color: #066;" class="styled-by-prettify">300</span><span style="color: #000;" class="styled-by-prettify"> </span><span style="color: #660;" class="styled-by-prettify">-</span><span style="color: #066;" class="styled-by-prettify">66.591148878993607</span><span style="color: #000;" class="styled-by-prettify"><br></span><span style="color: #066;" class="styled-by-prettify">350</span><span style="color: #000;" class="styled-by-prettify"> </span><span style="color: #660;" class="styled-by-prettify">-</span><span style="color: #066;" class="styled-by-prettify">66.590341443197801</span><span style="color: #000;" class="styled-by-prettify"><br></span><span style="color: #066;" class="styled-by-prettify">400</span><span style="color: #000;" class="styled-by-prettify"> </span><span style="color: #660;" class="styled-by-prettify">-</span><span style="color: #066;" class="styled-by-prettify">66.590268413708017</span><span style="color: #000;" class="styled-by-prettify"><br></span><span style="color: #066;" class="styled-by-prettify">450</span><span style="color: #000;" class="styled-by-prettify"> </span><span style="color: #660;" class="styled-by-prettify">-</span><span style="color: #066;" class="styled-by-prettify">66.590267280865888</span><span style="color: #000;" class="styled-by-prettify"><br></span><span style="color: #066;" class="styled-by-prettify">500</span><span style="color: #000;" class="styled-by-prettify"> </span><span style="color: #660;" class="styled-by-prettify">-</span><span style="color: #066;" class="styled-by-prettify">66.590221265788742</span></div></code></div><div><br></div><div><br></div><div><br></div><div></div></div><div class="prettyprint" style="background-color: rgb(250, 250, 250); border-color: rgb(187, 187, 187); border-style: solid; border-width: 1px; word-wrap: break-word;"><code class="prettyprint"><div class="subprettyprint"><span style="color: #606;" class="styled-by-prettify">Input</span><span style="color: #000;" class="styled-by-prettify"> </span><span style="color: #606;" class="styled-by-prettify">File</span><span style="color: #660;" class="styled-by-prettify">:</span><span style="color: #000;" class="styled-by-prettify"><br></span><span style="color: #660;" class="styled-by-prettify">&</span><span style="color: #000;" class="styled-by-prettify">GLOBAL<br> PROJECT maleimide</span><span style="color: #660;" class="styled-by-prettify">-</span><span style="color: #000;" class="styled-by-prettify">CUT50<br> RUN_TYPE ENERGY<br> PRINT_LEVEL MEDIUM<br></span><span style="color: #660;" class="styled-by-prettify">&</span><span style="color: #008;" class="styled-by-prettify">END</span><span style="color: #000;" class="styled-by-prettify"> GLOBAL<br></span><span style="color: #660;" class="styled-by-prettify">&</span><span style="color: #000;" class="styled-by-prettify">FORCE_EVAL<br> METHOD </span><span style="color: #606;" class="styled-by-prettify">Quickstep</span><span style="color: #000;" class="styled-by-prettify"><br> </span><span style="color: #660;" class="styled-by-prettify">&</span><span style="color: #000;" class="styled-by-prettify">SUBSYS<br>  </span><span style="color: #660;" class="styled-by-prettify">&</span><span style="color: #000;" class="styled-by-prettify">KIND C<br>   ELEMENT  C<br>   BASIS_SET DZVP</span><span style="color: #660;" class="styled-by-prettify">-</span><span style="color: #000;" class="styled-by-prettify">GTH</span><span style="color: #660;" class="styled-by-prettify">-</span><span style="color: #000;" class="styled-by-prettify">q4<br>   POTENTIAL GTH</span><span style="color: #660;" class="styled-by-prettify">-</span><span style="color: #000;" class="styled-by-prettify">BP</span><span style="color: #660;" class="styled-by-prettify">-</span><span style="color: #000;" class="styled-by-prettify">q4<br>  </span><span style="color: #660;" class="styled-by-prettify">&</span><span style="color: #008;" class="styled-by-prettify">END</span><span style="color: #000;" class="styled-by-prettify"> KIND<br>  </span><span style="color: #660;" class="styled-by-prettify">&</span><span style="color: #000;" class="styled-by-prettify">KIND N<br>   ELEMENT  N<br>   BASIS_SET DZVP</span><span style="color: #660;" class="styled-by-prettify">-</span><span style="color: #000;" class="styled-by-prettify">GTH</span><span style="color: #660;" class="styled-by-prettify">-</span><span style="color: #000;" class="styled-by-prettify">q5<br>   POTENTIAL GTH</span><span style="color: #660;" class="styled-by-prettify">-</span><span style="color: #000;" class="styled-by-prettify">BP</span><span style="color: #660;" class="styled-by-prettify">-</span><span style="color: #000;" class="styled-by-prettify">q5<br>  </span><span style="color: #660;" class="styled-by-prettify">&</span><span style="color: #008;" class="styled-by-prettify">END</span><span style="color: #000;" class="styled-by-prettify"> KIND<br>  </span><span style="color: #660;" class="styled-by-prettify">&</span><span style="color: #000;" class="styled-by-prettify">KIND O<br>   ELEMENT  O<br>   BASIS_SET DZVP</span><span style="color: #660;" class="styled-by-prettify">-</span><span style="color: #000;" class="styled-by-prettify">GTH</span><span style="color: #660;" class="styled-by-prettify">-</span><span style="color: #000;" class="styled-by-prettify">q6<br>   POTENTIAL GTH</span><span style="color: #660;" class="styled-by-prettify">-</span><span style="color: #000;" class="styled-by-prettify">BP</span><span style="color: #660;" class="styled-by-prettify">-</span><span style="color: #000;" class="styled-by-prettify">q6<br>  </span><span style="color: #660;" class="styled-by-prettify">&</span><span style="color: #008;" class="styled-by-prettify">END</span><span style="color: #000;" class="styled-by-prettify"> KIND<br>  </span><span style="color: #660;" class="styled-by-prettify">&</span><span style="color: #000;" class="styled-by-prettify">KIND H<br>   ELEMENT  H<br>   BASIS_SET DZVP</span><span style="color: #660;" class="styled-by-prettify">-</span><span style="color: #000;" class="styled-by-prettify">GTH</span><span style="color: #660;" class="styled-by-prettify">-</span><span style="color: #000;" class="styled-by-prettify">q1<br>   POTENTIAL GTH</span><span style="color: #660;" class="styled-by-prettify">-</span><span style="color: #000;" class="styled-by-prettify">BP</span><span style="color: #660;" class="styled-by-prettify">-</span><span style="color: #000;" class="styled-by-prettify">q1<br>  </span><span style="color: #660;" class="styled-by-prettify">&</span><span style="color: #008;" class="styled-by-prettify">END</span><span style="color: #000;" class="styled-by-prettify"> KIND<br>  </span><span style="color: #660;" class="styled-by-prettify">&</span><span style="color: #000;" class="styled-by-prettify">CELL<br>   A   </span><span style="color: #066;" class="styled-by-prettify">15.00000000</span><span style="color: #000;" class="styled-by-prettify">   </span><span style="color: #066;" class="styled-by-prettify">0.000000000</span><span style="color: #000;" class="styled-by-prettify">   </span><span style="color: #066;" class="styled-by-prettify">0.000000000</span><span style="color: #000;" class="styled-by-prettify"><br>   B   </span><span style="color: #066;" class="styled-by-prettify">0.000000000</span><span style="color: #000;" class="styled-by-prettify">   </span><span style="color: #066;" class="styled-by-prettify">15.00000000</span><span style="color: #000;" class="styled-by-prettify">   </span><span style="color: #066;" class="styled-by-prettify">0.000000000</span><span style="color: #000;" class="styled-by-prettify"><br>   C   </span><span style="color: #066;" class="styled-by-prettify">0.000000000</span><span style="color: #000;" class="styled-by-prettify">   </span><span style="color: #066;" class="styled-by-prettify">0.000000000</span><span style="color: #000;" class="styled-by-prettify">   </span><span style="color: #066;" class="styled-by-prettify">15.00000000</span><span style="color: #000;" class="styled-by-prettify"><br>  </span><span style="color: #660;" class="styled-by-prettify">&</span><span style="color: #008;" class="styled-by-prettify">END</span><span style="color: #000;" class="styled-by-prettify"> CELL<br>  </span><span style="color: #660;" class="styled-by-prettify">&</span><span style="color: #000;" class="styled-by-prettify">COORD<br>   C  </span><span style="color: #660;" class="styled-by-prettify">-</span><span style="color: #066;" class="styled-by-prettify">1.34450</span><span style="color: #000;" class="styled-by-prettify">  </span><span style="color: #660;" class="styled-by-prettify">-</span><span style="color: #066;" class="styled-by-prettify">0.60000</span><span style="color: #000;" class="styled-by-prettify">  </span><span style="color: #066;" class="styled-by-prettify">0.00000</span><span style="color: #000;" class="styled-by-prettify"> <br>   C  </span><span style="color: #660;" class="styled-by-prettify">-</span><span style="color: #066;" class="styled-by-prettify">1.34450</span><span style="color: #000;" class="styled-by-prettify">  </span><span style="color: #066;" class="styled-by-prettify">0.75700</span><span style="color: #000;" class="styled-by-prettify">  </span><span style="color: #066;" class="styled-by-prettify">0.00000</span><span style="color: #000;" class="styled-by-prettify"> <br>   C  </span><span style="color: #660;" class="styled-by-prettify">-</span><span style="color: #066;" class="styled-by-prettify">0.02500</span><span style="color: #000;" class="styled-by-prettify">  </span><span style="color: #660;" class="styled-by-prettify">-</span><span style="color: #066;" class="styled-by-prettify">0.91990</span><span style="color: #000;" class="styled-by-prettify">  </span><span style="color: #066;" class="styled-by-prettify">0.00000</span><span style="color: #000;" class="styled-by-prettify"> <br>   C  </span><span style="color: #660;" class="styled-by-prettify">-</span><span style="color: #066;" class="styled-by-prettify">0.02500</span><span style="color: #000;" class="styled-by-prettify">  </span><span style="color: #066;" class="styled-by-prettify">1.07680</span><span style="color: #000;" class="styled-by-prettify">  </span><span style="color: #066;" class="styled-by-prettify">0.00000</span><span style="color: #000;" class="styled-by-prettify"> <br>   N   </span><span style="color: #066;" class="styled-by-prettify">0.91900</span><span style="color: #000;" class="styled-by-prettify">  </span><span style="color: #066;" class="styled-by-prettify">0.07840</span><span style="color: #000;" class="styled-by-prettify">  </span><span style="color: #066;" class="styled-by-prettify">0.00000</span><span style="color: #000;" class="styled-by-prettify"> <br>   O   </span><span style="color: #066;" class="styled-by-prettify">0.31260</span><span style="color: #000;" class="styled-by-prettify">  </span><span style="color: #660;" class="styled-by-prettify">-</span><span style="color: #066;" class="styled-by-prettify">2.08220</span><span style="color: #000;" class="styled-by-prettify">  </span><span style="color: #066;" class="styled-by-prettify">0.00000</span><span style="color: #000;" class="styled-by-prettify"> <br>   O   </span><span style="color: #066;" class="styled-by-prettify">0.31270</span><span style="color: #000;" class="styled-by-prettify">  </span><span style="color: #066;" class="styled-by-prettify">2.23910</span><span style="color: #000;" class="styled-by-prettify">  </span><span style="color: #066;" class="styled-by-prettify">0.00000</span><span style="color: #000;" class="styled-by-prettify"> <br>   H  </span><span style="color: #660;" class="styled-by-prettify">-</span><span style="color: #066;" class="styled-by-prettify">2.23620</span><span style="color: #000;" class="styled-by-prettify">  </span><span style="color: #660;" class="styled-by-prettify">-</span><span style="color: #066;" class="styled-by-prettify">1.24920</span><span style="color: #000;" class="styled-by-prettify">  </span><span style="color: #066;" class="styled-by-prettify">0.00000</span><span style="color: #000;" class="styled-by-prettify"> <br>   H  </span><span style="color: #660;" class="styled-by-prettify">-</span><span style="color: #066;" class="styled-by-prettify">2.23620</span><span style="color: #000;" class="styled-by-prettify">  </span><span style="color: #066;" class="styled-by-prettify">1.40620</span><span style="color: #000;" class="styled-by-prettify">  </span><span style="color: #066;" class="styled-by-prettify">0.00000</span><span style="color: #000;" class="styled-by-prettify"> <br>   H   </span><span style="color: #066;" class="styled-by-prettify">1.92530</span><span style="color: #000;" class="styled-by-prettify">  </span><span style="color: #066;" class="styled-by-prettify">0.07840</span><span style="color: #000;" class="styled-by-prettify">  </span><span style="color: #066;" class="styled-by-prettify">0.00000</span><span style="color: #000;" class="styled-by-prettify"> <br>  </span><span style="color: #660;" class="styled-by-prettify">&</span><span style="color: #008;" class="styled-by-prettify">END</span><span style="color: #000;" class="styled-by-prettify"> COORD<br> </span><span style="color: #660;" class="styled-by-prettify">&</span><span style="color: #008;" class="styled-by-prettify">END</span><span style="color: #000;" class="styled-by-prettify"> SUBSYS<br> </span><span style="color: #660;" class="styled-by-prettify">&</span><span style="color: #000;" class="styled-by-prettify">DFT<br>  BASIS_SET_FILE_NAME  GTH_BASIS_SETS<br>  POTENTIAL_FILE_NAME  GTH_POTENTIALS<br>  </span><span style="color: #660;" class="styled-by-prettify">&</span><span style="color: #000;" class="styled-by-prettify">QS<br>   EPS_DEFAULT </span><span style="color: #066;" class="styled-by-prettify">1.0E-9</span><span style="color: #000;" class="styled-by-prettify"><br>  </span><span style="color: #660;" class="styled-by-prettify">&</span><span style="color: #008;" class="styled-by-prettify">END</span><span style="color: #000;" class="styled-by-prettify"> QS<br>  </span><span style="color: #660;" class="styled-by-prettify">&</span><span style="color: #000;" class="styled-by-prettify">MGRID<br>   NGRIDS </span><span style="color: #066;" class="styled-by-prettify">4</span><span style="color: #000;" class="styled-by-prettify"><br>   CUTOFF </span><span style="color: #066;" class="styled-by-prettify">50</span><span style="color: #000;" class="styled-by-prettify"><br>   REL_CUTOFF </span><span style="color: #066;" class="styled-by-prettify">60</span><span style="color: #000;" class="styled-by-prettify"><br>  </span><span style="color: #660;" class="styled-by-prettify">&</span><span style="color: #008;" class="styled-by-prettify">END</span><span style="color: #000;" class="styled-by-prettify"> MGRID<br>  </span><span style="color: #660;" class="styled-by-prettify">&</span><span style="color: #000;" class="styled-by-prettify">XC<br>   </span><span style="color: #660;" class="styled-by-prettify">&</span><span style="color: #000;" class="styled-by-prettify">XC_FUNCTIONAL BP<br>   </span><span style="color: #660;" class="styled-by-prettify">&</span><span style="color: #008;" class="styled-by-prettify">END</span><span style="color: #000;" class="styled-by-prettify"> XC_FUNCTIONAL<br>  </span><span style="color: #660;" class="styled-by-prettify">&</span><span style="color: #008;" class="styled-by-prettify">END</span><span style="color: #000;" class="styled-by-prettify"> XC<br>  </span><span style="color: #660;" class="styled-by-prettify">&</span><span style="color: #000;" class="styled-by-prettify">SCF<br>   SCF_GUESS ATOMIC<br>   EPS_SCF </span><span style="color: #066;" class="styled-by-prettify">1.0E-7</span><span style="color: #000;" class="styled-by-prettify"><br>   MAX_SCF </span><span style="color: #066;" class="styled-by-prettify">1</span><span style="color: #000;" class="styled-by-prettify"><br>   </span><span style="color: #660;" class="styled-by-prettify">&</span><span style="color: #000;" class="styled-by-prettify">DIAGONALIZATION  ON<br>    ALGORITHM STANDARD<br>   </span><span style="color: #660;" class="styled-by-prettify">&</span><span style="color: #008;" class="styled-by-prettify">END</span><span style="color: #000;" class="styled-by-prettify"> DIAGONALIZATION<br>   </span><span style="color: #660;" class="styled-by-prettify">&</span><span style="color: #000;" class="styled-by-prettify">MIXING  T<br>    METHOD BROYDEN_MIXING<br>    ALPHA </span><span style="color: #066;" class="styled-by-prettify">0.4</span><span style="color: #000;" class="styled-by-prettify"><br>    BETA </span><span style="color: #066;" class="styled-by-prettify">0.5</span><span style="color: #000;" class="styled-by-prettify"><br>    NBROYDEN </span><span style="color: #066;" class="styled-by-prettify">8</span><span style="color: #000;" class="styled-by-prettify"><br>   </span><span style="color: #660;" class="styled-by-prettify">&</span><span style="color: #008;" class="styled-by-prettify">END</span><span style="color: #000;" class="styled-by-prettify"> MIXING<br>  </span><span style="color: #660;" class="styled-by-prettify">&</span><span style="color: #008;" class="styled-by-prettify">END</span><span style="color: #000;" class="styled-by-prettify"> SCF<br> </span><span style="color: #660;" class="styled-by-prettify">&</span><span style="color: #008;" class="styled-by-prettify">END</span><span style="color: #000;" class="styled-by-prettify"> DFT<br> </span><span style="color: #660;" class="styled-by-prettify">&</span><span style="color: #000;" class="styled-by-prettify">PRINT<br>  </span><span style="color: #660;" class="styled-by-prettify">&</span><span style="color: #000;" class="styled-by-prettify">TOTAL_NUMBERS ON<br>  </span><span style="color: #660;" class="styled-by-prettify">&</span><span style="color: #008;" class="styled-by-prettify">END</span><span style="color: #000;" class="styled-by-prettify"> TOTAL_NUMBERS<br> </span><span style="color: #660;" class="styled-by-prettify">&</span><span style="color: #008;" class="styled-by-prettify">END</span><span style="color: #000;" class="styled-by-prettify"> PRINT<br></span><span style="color: #660;" class="styled-by-prettify">&</span><span style="color: #008;" class="styled-by-prettify">END</span><span style="color: #000;" class="styled-by-prettify"> FORCE_EVAL</span></div></code></div><div><div><br></div></div><div><br></div><div>Evgeniy </div></div>