<div dir="ltr"><div>The problem seems to be related to the "GEEP" QM/MM coupling as the problem doesn't happen with the mechanical coupling. </div><div>I think I'm using correct parameters for GEEP and my DFT settings seem to be reasonable too. Does anyone know how to solve this issue?</div><div><br></div><div>Thanks,</div><div>Sal </div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><br><br>On Thursday, December 6, 2018 at 9:57:42 AM UTC-8, Sal wrote:<blockquote class="gmail_quote" style="margin: 0;margin-left: 0.8ex;border-left: 1px #ccc solid;padding-left: 1ex;"><div dir="ltr">
<p><span><font face="times new roman, serif">Dear CP2K developers,</font></span></p>
<p><font face="times new roman, serif"><span></span><br></font></p>
<p><span><font face="times new roman, serif">I am running periodic QM/MM simulation (BLYP/TZV2P with GTH-BLYP) that includes water, protein and lipid. </font></span></p>
<p><span><font face="times new roman, serif">Problem is that </font></span><span style="font-family:"times new roman",serif">few </span><span style="font-family:"times new roman",serif">water molecules are pushed against the edge even with a hard quadratic wall (K=40 kcalmol/angstrom^2).</span></p><p><span style="font-family:"times new roman",serif">QM cell dimensions are chosen to be ~2 A larger than QM size.</span></p>
<p><span><font face="times new roman, serif">I am wondering if you know any specific parameter setting (e. g. # of LIB in GEEP, NGRIDS, GPW cutoffs, ...) would cause this.</font></span></p>
<p><font face="times new roman, serif"><span></span><br></font></p><p><font face="times new roman, serif"><br></font></p><p><font face="times new roman, serif"><br></font></p><p><font face="times new roman, serif"><br></font></p><p><font face="times new roman, serif">Thanks for your time,</font></p><p><font face="times new roman, serif">Sal</font></p><p><font face="times new roman, serif"><br></font></p><p><font face="times new roman, serif"><br></font></p><p><font face="times new roman, serif"><br></font></p><p><font face="times new roman, serif"><br></font></p>
<p><span><font face="times new roman, serif">More detail about my QM/MM setup:</font></span></p>
<p><span></span><br></p>
<p><span></span><br></p>
<p><span></span><br></p>
<p><span><span> </span>&MGRID<span> </span></span></p>
<p><span><span> </span>COMMENSURATE</span></p>
<p><span><span> </span>&RS_GRID</span></p>
<p><span><span> </span>DISTRIBUTION_TYPE DISTRIBUTED</span></p>
<p><span><span> </span>&END RS_GRID</span></p>
<p><span><span> </span>CUTOFF 360</span></p>
<p><span><span> </span>NGRIDS 4</span></p>
<p><span><span> </span>REL_CUTOFF 60</span></p>
<p><span><span> </span>&END MGRID <span> </span></span></p>
<p><span><br>
</span></p>
<p><span><span> </span>&QS<span> </span></span></p>
<p><span><span> </span>METHOD GPW <span> </span></span></p>
<p><span><span> </span>EPS_DEFAULT 1.0E-10<span> </span></span></p>
<p><span><span> </span>MAP_CONSISTENT TRUE<span> </span></span></p>
<p><span><span> </span>EXTRAPOLATION ASPC <span> </span></span></p>
<p><span><span> </span>EXTRAPOLATION_ORDER 3<span> </span></span></p>
<p><span><span> </span>&END QS<span> </span></span></p>
<p><span><br>
</span></p>
<p><span><span> </span>&SCF <span> </span></span></p>
<p><span><span> </span>MAX_SCF 30<span> </span></span></p>
<p><span><span> </span>EPS_SCF 1.0E-6</span></p>
<p><span><span> </span>SCF_GUESS RESTART</span></p>
<p><span>#<span> </span>SCF_GUESS ATOMIC</span></p>
<p><span><span> </span>&OT T</span></p>
<p><span><span> </span>MINIMIZER DIIS<br>
</span></p>
<p><span><span> </span>N_DIIS 7</span></p>
<p><span><span> </span>&END OT</span></p>
<p><span><span> </span>&OUTER_SCF</span></p>
<p><span><span> </span>MAX_SCF 3</span></p>
<p><span><span> </span>EPS_SCF 1.0E-6</span></p>
<p><span><span> </span>&END OUTER_SCF<span> </span></span></p>
<p><span><br>
</span><span><span> </span>&XC <span> </span></span></p>
<p><span><span> </span>&XC_FUNCTIONAL BLYP</span></p>
<p><span><span> </span>&END XC_FUNCTIONAL</span></p>
<p><span><span> </span>&VDW_POTENTIAL <span> </span></span></p>
<p><span><span> </span>POTENTIAL_TYPE<span> </span>PAIR_POTENTIAL</span></p>
<p><span><span> </span>&PAIR_POTENTIAL<span> </span></span></p>
<p><span><span> </span>TYPE<span> </span>DFTD3</span></p>
<p><span><span> </span>PARAMETER_FILE_NAME<span> </span>dftd3.dat</span></p>
<p><span><span> </span>REFERENCE_FUNCTIONAL BLYP</span></p>
<p><span><span> </span>&END PAIR_POTENTIAL</span></p>
<p><span><span> </span>&END VDW_POTENTIAL</span></p>
<p><span><span> </span>&END XC<span> </span></span></p>
<p><span></span><br></p>
<p><span> </span></p>
<p><span> </span></p>
<p><span>.....</span></p>
<p><span>.....</span></p>
<p><span>.....</span></p>
<p><span></span><br></p>
<p><span><span> </span>E_COUPL GAUSS</span></p>
<p><span><span> </span>USE_GEEP_LIB<span> </span>9</span></p>
<p><span><span> </span>&PERIODIC<span> </span></span></p>
<p><span><span> </span>GMAX 1.0</span></p>
<p><span><span> </span>&MULTIPOLE<span> </span></span></p>
<p><span><span> </span>EWALD_PRECISION 1.0E-6</span></p>
<p><span>#<span> </span>NGRIDS<span> </span>16 16 24</span></p>
<p><span><span> </span>ANALYTICAL_GTERM<span> </span></span></p>
<p><span><span> </span>RCUT<span> </span>14.0</span></p>
<p><span><span> </span>&END MULTIPOLE</span></p>
<p><span><span> </span>&END PERIODIC</span></p>
<p><span><br>
</span></p>
<p><span><span> </span>&CELL</span></p>
<p><span><span> </span>ABC [angstrom] 15 16 22</span></p>
<p><span><br>
</span></p>
<p><span><span> </span>PERIODIC XYZ<span> </span></span></p>
<p><span><span> </span>&END CELL</span></p>
<p><span><span> </span>CENTER NEVER</span></p>
<p><span><span> </span>&WALLS<span> </span></span></p>
<p><span><span> </span>type quadratic</span></p>
<p><span><span> </span>k [kcalmol/angstrom^2] 40.0</span></p>
<p><span><span> </span>WALL_SKIN<span> </span>1.0 1.0 1.0</span></p>
<p><span><span> </span>&END WALLS<span> </span></span></p></div></blockquote></div>