<div dir="ltr">Dear Dorothea,<br><br>Thank you for the invaluable suggestion.  <br>While your answer makes perfect sense to me, I just found out that CP2K 2.5.1 does not have option to turn off QMMM/PERIODIC/MULTIPOLE using the section parameter OFF.<br>Therefore, CP2K 2.5.1 produces the same (diverging) energy profile whether I set &MULTIPOLE OFF or not.<br><br>I will install version 2.6 and try it again.<br><br>Best regards,<br><br>Jonggu<br><br><br>2015년 3월 18일 수요일 오후 6시 22분 40초 UTC+9, Dorothea Golze 님의 말:<blockquote class="gmail_quote" style="margin: 0;margin-left: 0.8ex;border-left: 1px #ccc solid;padding-left: 1ex;"><div dir="ltr"><div><div><div><div><div><div>Hi,<br><br></div>if you have a fully periodic setup where the QM and MM boxes are equal, you do not need the decoupling/recoupling stuff, i.e. switch off explicitly the MULTIPOLE section like that<br>&MULTIPOLE OFF<br></div>&END<br><br></div>Also set in the QMMM section<br><br> &WALLS<br>     TYPE NONE<br>  &END WALLS<br><br></div>That should address your first question...<br><br></div>Cheers,<br></div>Dorothea<br><div><div><div><div><div> <br></div></div></div></div></div></div><div><br><div class="gmail_quote">2015-03-18 8:46 GMT+01:00 Jonggu Jeon <span dir="ltr"><<a href="javascript:" target="_blank" gdf-obfuscated-mailto="Z-miH6AKlU0J" rel="nofollow" onmousedown="this.href='javascript:';return true;" onclick="this.href='javascript:';return true;">jeon...@gmail.com</a>></span>:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Dear CP2K users,<br><br>I'd like to ask some questions on the capabilities of the QM/MM part of CP2K (I'm using version 2.5.1, svn:13632).<br><br>I've been attempting a QM/MM MD simulation with CP2K. My system consists of one NMA molecule (TZV2P/BLYP DFT) and 48 methanol molecules (OPLS MM force field).<br>The relevant parts of my input file are attached at the end of the message. Basically, I'm following all the advices from this group for a fully periodic QM/MM setup and set the cell sizes for the QM (in QMMM/CELL) and MM (in SUBSYS/CELL) parts equal.<br><br>The following is the summary of my findings.<br><br>1. With FORCE_EVAL/QMMM/CENTER EVERY_STEP, the total energy is not conserved, as pointed out by Dr. Laino in this group before.<br>2. With FORCE_EVAL/QMMM/CENTER SETUP_ONLY, the total energy is very well conserved within 0.1 kcal/mol for a few ps until the QM molecule eventually crosses the cell boundary.  At this point system energy shoots up by several kcal/mol and the output begins to produce the following messages:<br><br> *** 16:11:03 WARNING in qmmm_util:apply_qmmm_walls_<wbr>reflective :: One or  ***<br> *** few QM atoms are within the SKIN of the quantum box. Check your run  ***<br> *** and you may possibly consider: the activation of the QMMM WALLS      ***<br> *** around the QM box, switching ON the centering of the QM box or       ***<br> *** increase the size of the QM cell. CP2K CONTINUE but results could be ***<br> *** meaningless. qmmm_util.F line 206                           <wbr>         ***<br><br>My questions are as follows:<br><br>1. Is it possible to achieve the energy conservation in a fully periodic DFT/MM MD without worrying about the QM molecule crossing the cell boundary? I believe this is possible in full DFT MD but my experience on CP2K QM/MM so far indicates otherwise. I'd appreciate if someone can provide an answer and keywords to achieve it.<br><br>2. The QMMM/CENTER option affects energy conservation a lot. When CENTER EVERY_STEP is used, would it improve energy conservation if I use finer grids by increasing DFT/MGRID/CUTOFF value?<br><br>The skeletal form of my input file is attached below.<br>Thank you.<br><br>Jonggu Jeon<br><br><br><br> &MOTION<br>   &MD<br>     ENSEMBLE  NVE<br>     STEPS  40000<br>     TIMESTEP     0.5<br>     STEP_START_VAL  0<br>     TIME_START_VAL    0<br>   &END MD<br> &END MOTION<br> &FORCE_EVAL<br>   METHOD  QMMM<br>   &DFT<br>     BASIS_SET_FILE_NAME /opt/cp2k/2.5.1/tests/QS/GTH_<wbr>BASIS_SETS<br>     POTENTIAL_FILE_NAME /opt/cp2k/2.5.1/tests/QS/<wbr>POTENTIAL<br>     WFN_RESTART_FILE_NAME wfn.rst<br>     CHARGE  0<br>     &SCF<br>       MAX_SCF  30<br>       EPS_SCF     9.9999999999999995E-07<br>       SCF_GUESS  RESTART<br>       &OT  T<br>         MINIMIZER  DIIS<br>         PRECONDITIONER  FULL_ALL<br>         ENERGY_GAP     1.0000000000000000E-03<br>       &END OT<br>       &OUTER_SCF  T<br>         EPS_SCF     9.9999999999999995E-07<br>         MAX_SCF  1<br>       &END OUTER_SCF<br>     &END SCF<br>     &QS<br>       EPS_DEFAULT     1.0000000000000000E-10<br>       MAP_CONSISTENT  T<br>       EXTRAPOLATION  ASPC<br>       EXTRAPOLATION_ORDER  3<br>       METHOD  GPW<br>     &END QS<br>     &MGRID<br>       CUTOFF     2.8000000000000000E+02<br>       COMMENSURATE  T<br>     &END MGRID<br>     &XC<br>       &XC_GRID<br>         XC_SMOOTH_RHO  NN50<br>         XC_DERIV  SPLINE2_SMOOTH<br>       &END XC_GRID<br>       &XC_FUNCTIONAL  NO_SHORTCUT<br>         &BECKE88  T<br>         &END BECKE88<br>         &LYP  T<br>         &END LYP<br>       &END XC_FUNCTIONAL<br>       &VDW_POTENTIAL<br>         POTENTIAL_TYPE  PAIR_POTENTIAL<br>         &PAIR_POTENTIAL<br>           TYPE  DFTD3<br>           PARAMETER_FILE_NAME /opt/cp2k/2.5.1/tests/QS/<wbr>dftd3.dat<br>           REFERENCE_FUNCTIONAL BLYP<br>           CALCULATE_C9_TERM  F<br>           REFERENCE_C9_TERM  F<br>           LONG_RANGE_CORRECTION  F<br>         &END PAIR_POTENTIAL<br>       &END VDW_POTENTIAL<br>     &END XC<br>   &END DFT<br>   &MM<br>     &FORCEFIELD<br>       PARMTYPE  AMBER<br>       PARM_FILE_NAME ndmd48.ao.prmtop<br>       &SPLINE<br>         EMAX_SPLINE     1.0000000000000000E+00<br>       &END SPLINE<br>     &END FORCEFIELD<br>     &POISSON<br>       &EWALD<br>         EWALD_TYPE  SPME<br>         ALPHA     3.4999999999999998E-01<br>         GMAX  18<br>       &END EWALD<br>     &END POISSON<br>   &END MM<br>   &QMMM<br>     E_COUPL  GAUSS<br>     USE_GEEP_LIB  7<br>     NOCOMPATIBILITY  T<br>     CENTER  SETUP_ONLY<br>     INITIAL_TRANSLATION_VECTOR    -1.0888775605157457E+01   -2.9066675351256084E+00    7.3922596274008097E+00<br>     &CELL<br>       ABC     1.5084868700000001E+01    1.5084868700000001E+01    1.5084868700000001E+01<br>       PERIODIC  XYZ<br>     &END CELL<br>     &PERIODIC<br>       GMAX     5.0000000000000000E-01<br>       &MULTIPOLE<br>         RCUT     1.2000000000000000E+01<br>         EWALD_PRECISION     4.9999999999999998E-07<br>         ANALYTICAL_GTERM  T<br>         NGRIDS  50 50 50<br>       &END MULTIPOLE<br>     &END PERIODIC<br>   &END QMMM<br>   &SUBSYS<br>     &CELL<br>       A     1.5084868700000001E+01    0.0000000000000000E+00    0.0000000000000000E+00<br>       B     0.0000000000000000E+00    1.5084868700000001E+01    0.0000000000000000E+00<br>       C     0.0000000000000000E+00    0.0000000000000000E+00    1.5084868700000001E+01<br>       MULTIPLE_UNIT_CELL  1 1 1<br>     &END CELL<br>     &TOPOLOGY<br>       NUMBER_OF_ATOMS  156<br>       CONN_FILE_NAME ndmd48.ao.prmtop<br>       CONN_FILE_FORMAT  AMBER<br>       MULTIPLE_UNIT_CELL  1 1 1<br>     &END TOPOLOGY<br>   &END SUBSYS<br> &END FORCE_EVAL<span><font color="#888888"><br><br></font></span></div><span><font color="#888888">

<p></p>

-- <br>
You received this message because you are subscribed to the Google Groups "cp2k" group.<br>
To unsubscribe from this group and stop receiving emails from it, send an email to <a href="javascript:" target="_blank" gdf-obfuscated-mailto="Z-miH6AKlU0J" rel="nofollow" onmousedown="this.href='javascript:';return true;" onclick="this.href='javascript:';return true;">cp2k+uns...@googlegroups.<wbr>com</a>.<br>
To post to this group, send email to <a href="javascript:" target="_blank" gdf-obfuscated-mailto="Z-miH6AKlU0J" rel="nofollow" onmousedown="this.href='javascript:';return true;" onclick="this.href='javascript:';return true;">cp...@googlegroups.com</a>.<br>
Visit this group at <a href="http://groups.google.com/group/cp2k" target="_blank" rel="nofollow" onmousedown="this.href='http://groups.google.com/group/cp2k';return true;" onclick="this.href='http://groups.google.com/group/cp2k';return true;">http://groups.google.com/<wbr>group/cp2k</a>.<br>
For more options, visit <a href="https://groups.google.com/d/optout" target="_blank" rel="nofollow" onmousedown="this.href='https://groups.google.com/d/optout';return true;" onclick="this.href='https://groups.google.com/d/optout';return true;">https://groups.google.com/d/<wbr>optout</a>.<br>
</font></span></blockquote></div><br></div>
</blockquote></div>